diff --git a/CHANGELOG.md b/CHANGELOG.md
index 505c04169..a8bb48e9f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,8 @@
 ## Current Master
 
 - Add new support for new eth_signTypedData method per EIP 712.
+- Fix bug where some transactions would be shown as pending forever, even after successfully mined.
+- Fix bug where a transaction might be shown as pending forever if another tx with the same nonce was mined.
 
 ## 3.10.9 2017-10-5
 
diff --git a/app/scripts/controllers/transactions.js b/app/scripts/controllers/transactions.js
index a0f983deb..ef659a300 100644
--- a/app/scripts/controllers/transactions.js
+++ b/app/scripts/controllers/transactions.js
@@ -62,6 +62,7 @@ module.exports = class TransactionController extends EventEmitter {
       retryTimePeriod: 86400000, // Retry 3500 blocks, or about 1 day.
       publishTransaction: (rawTx) => this.query.sendRawTransaction(rawTx),
       getPendingTransactions: this.txStateManager.getPendingTransactions.bind(this.txStateManager),
+      getCompletedTransactions: this.txStateManager.getConfirmedTransactions.bind(this.txStateManager),
     })
 
     this.txStateManager.store.subscribe(() => this.emit('update:badge'))
diff --git a/app/scripts/lib/pending-tx-tracker.js b/app/scripts/lib/pending-tx-tracker.js
index 8a626e222..df504c126 100644
--- a/app/scripts/lib/pending-tx-tracker.js
+++ b/app/scripts/lib/pending-tx-tracker.js
@@ -25,7 +25,9 @@ module.exports = class PendingTransactionTracker extends EventEmitter {
     // default is one day
     this.retryTimePeriod = config.retryTimePeriod || 86400000
     this.getPendingTransactions = config.getPendingTransactions
+    this.getCompletedTransactions = config.getCompletedTransactions
     this.publishTransaction = config.publishTransaction
+    this._checkPendingTxs()
   }
 
   //  checks if a signed tx is in a block and
@@ -120,6 +122,7 @@ module.exports = class PendingTransactionTracker extends EventEmitter {
   async _checkPendingTx (txMeta) {
     const txHash = txMeta.hash
     const txId = txMeta.id
+
     // extra check in case there was an uncaught error during the
     // signature and submission process
     if (!txHash) {
@@ -128,6 +131,15 @@ module.exports = class PendingTransactionTracker extends EventEmitter {
       this.emit('tx:failed', txId, noTxHashErr)
       return
     }
+
+    // If another tx with the same nonce is mined, set as failed.
+    const taken = await this._checkIfNonceIsTaken(txMeta)
+    if (taken) {
+      const nonceTakenErr = new Error('Another transaction with this nonce has been mined.')
+      nonceTakenErr.name = 'NonceTakenErr'
+      return this.emit('tx:failed', txId, nonceTakenErr)
+    }
+
     // get latest transaction status
     let txParams
     try {
@@ -159,4 +171,13 @@ module.exports = class PendingTransactionTracker extends EventEmitter {
     }
     nonceGlobalLock.releaseLock()
   }
+
+  async _checkIfNonceIsTaken (txMeta) {
+    const completed = this.getCompletedTransactions()
+    const sameNonce = completed.filter((otherMeta) => {
+      return otherMeta.txParams.nonce === txMeta.txParams.nonce
+    })
+    return sameNonce.length > 0
+  }
+
 }
diff --git a/app/scripts/lib/tx-state-manager.js b/app/scripts/lib/tx-state-manager.js
index cf8117864..2250403f6 100644
--- a/app/scripts/lib/tx-state-manager.js
+++ b/app/scripts/lib/tx-state-manager.js
@@ -46,6 +46,12 @@ module.exports = class TransactionStateManger extends EventEmitter {
     return this.getFilteredTxList(opts)
   }
 
+  getConfirmedTransactions (address) {
+    const opts = { status: 'confirmed' }
+    if (address) opts.from = address
+    return this.getFilteredTxList(opts)
+  }
+
   addTx (txMeta) {
     this.once(`${txMeta.id}:signed`, function (txId) {
       this.removeAllListeners(`${txMeta.id}:rejected`)
@@ -242,4 +248,4 @@ module.exports = class TransactionStateManger extends EventEmitter {
   _saveTxList (transactions) {
     this.store.updateState({ transactions })
   }
-}
\ No newline at end of file
+}
diff --git a/test/unit/pending-tx-test.js b/test/unit/pending-tx-test.js
index 6b62bb5b1..32421a44f 100644
--- a/test/unit/pending-tx-test.js
+++ b/test/unit/pending-tx-test.js
@@ -5,6 +5,8 @@ const ObservableStore = require('obs-store')
 const clone = require('clone')
 const { createStubedProvider } = require('../stub/provider')
 const PendingTransactionTracker = require('../../app/scripts/lib/pending-tx-tracker')
+const MockTxGen = require('../lib/mock-tx-gen')
+const sinon = require('sinon')
 const noop = () => true
 const currentNetworkId = 42
 const otherNetworkId = 36
@@ -46,10 +48,60 @@ describe('PendingTransactionTracker', function () {
         }
       },
       getPendingTransactions: () => {return []},
+      getCompletedTransactions: () => {return []},
       publishTransaction: () => {},
     })
   })
 
+  describe('_checkPendingTx state management', function () {
+    let stub
+
+    afterEach(function () {
+      if (stub) {
+        stub.restore()
+      }
+    })
+
+    it('should become failed if another tx with the same nonce succeeds', async function () {
+
+      // SETUP
+      const txGen = new MockTxGen()
+
+      txGen.generate({
+        id: '456',
+        value: '0x01',
+        hash: '0xbad',
+        status: 'confirmed',
+        nonce: '0x01',
+      }, { count: 1 })
+
+      const pending = txGen.generate({
+        id: '123',
+        value: '0x02',
+        hash: '0xfad',
+        status: 'submitted',
+        nonce: '0x01',
+      }, { count: 1 })[0]
+
+      stub = sinon.stub(pendingTxTracker, 'getCompletedTransactions')
+      .returns(txGen.txs)
+
+      // THE EXPECTATION
+      const spy = sinon.spy()
+      pendingTxTracker.on('tx:failed', (txId, err) => {
+        assert.equal(txId, pending.id, 'should fail the pending tx')
+        assert.equal(err.name, 'NonceTakenErr', 'should emit a nonce taken error.')
+        spy(txId, err)
+      })
+
+      // THE METHOD
+      await pendingTxTracker._checkPendingTx(pending)
+
+      // THE ASSERTION
+      assert.ok(spy.calledWith(pending.id), 'tx failed should be emitted')
+    })
+  })
+
   describe('#checkForTxInBlock', function () {
     it('should return if no pending transactions', function () {
       // throw a type error if it trys to do anything on the block
@@ -239,4 +291,4 @@ describe('PendingTransactionTracker', function () {
     })
   })
  })
-})
\ No newline at end of file
+})