diff --git a/qa/rpc-tests/auxpow.py b/qa/rpc-tests/auxpow.py
index 31228a730..754577c51 100755
--- a/qa/rpc-tests/auxpow.py
+++ b/qa/rpc-tests/auxpow.py
@@ -61,7 +61,7 @@ class AuxPOWTest (BitcoinTestFramework):
                 raise ex
         self.sync_all()
 
-        # 5. mine blocks until we're in in auxpow era
+        # 5. mine blocks until we're in auxpow era
         self.nodes[1].generate(self.AUXPOW_START - self.DIGISHIELD_START)
         self.sync_all()
 
diff --git a/qa/rpc-tests/test_framework/mininode.py b/qa/rpc-tests/test_framework/mininode.py
index 958645c4e..980feaa4b 100755
--- a/qa/rpc-tests/test_framework/mininode.py
+++ b/qa/rpc-tests/test_framework/mininode.py
@@ -63,7 +63,7 @@ mininode_socket_map = dict()
 
 # One lock for synchronizing all data access between the networking thread (see
 # NetworkThread below) and the thread running the test logic.  For simplicity,
-# NodeConn acquires this lock whenever delivering a message to to a NodeConnCB,
+# NodeConn acquires this lock whenever delivering a message to a NodeConnCB,
 # and whenever adding anything to the send buffer (in send_message()).  This
 # lock should be acquired in the thread running the test logic to synchronize
 # access to any data shared with the NodeConnCB or NodeConn.
diff --git a/src/qt/walletmodel.cpp b/src/qt/walletmodel.cpp
index 593a0fd52..380291d85 100644
--- a/src/qt/walletmodel.cpp
+++ b/src/qt/walletmodel.cpp
@@ -342,7 +342,7 @@ WalletModel::SendCoinsReturn WalletModel::sendCoins(WalletModelTransaction &tran
         transaction_array.append(&(ssTx[0]), ssTx.size());
     }
 
-    // Add addresses / update labels that we've sent to to the address book,
+    // Add addresses / update labels that we've sent to the address book,
     // and emit coinsSent signal for each recipient
     Q_FOREACH(const SendCoinsRecipient &rcp, transaction.getRecipients())
     {
diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index 49de7befa..80688d005 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -135,7 +135,7 @@ void CTxMemPool::UpdateTransactionsFromBlock(const std::vector<uint256> &vHashes
     // accounted for in the state of their ancestors)
     std::set<uint256> setAlreadyIncluded(vHashesToUpdate.begin(), vHashesToUpdate.end());
 
-    // Iterate in reverse, so that whenever we are looking at at a transaction
+    // Iterate in reverse, so that whenever we are looking at a transaction
     // we are sure that all in-mempool descendants have already been processed.
     // This maximizes the benefit of the descendant cache and guarantees that
     // setMemPoolChildren will be updated, an assumption made in