diff --git a/unreleased_history/bug_fixes/prevent_duplicate_txn_name.md b/unreleased_history/bug_fixes/prevent_duplicate_txn_name.md
new file mode 100644
index 0000000000..152869d7d2
--- /dev/null
+++ b/unreleased_history/bug_fixes/prevent_duplicate_txn_name.md
@@ -0,0 +1 @@
+Fix a race condition in pessimistic transactions that could allow multiple transactions with the same name to be registered simultaneously, resulting in a crash or other unpredictable behavior.
diff --git a/utilities/transactions/pessimistic_transaction.cc b/utilities/transactions/pessimistic_transaction.cc
index b572014dad..45f84ef9f3 100644
--- a/utilities/transactions/pessimistic_transaction.cc
+++ b/utilities/transactions/pessimistic_transaction.cc
@@ -1247,14 +1247,15 @@ Status PessimisticTransaction::SetName(const TransactionName& name) {
   if (txn_state_ == STARTED) {
     if (name_.length()) {
       s = Status::InvalidArgument("Transaction has already been named.");
-    } else if (txn_db_impl_->GetTransactionByName(name) != nullptr) {
-      s = Status::InvalidArgument("Transaction name must be unique.");
     } else if (name.length() < 1 || name.length() > 512) {
       s = Status::InvalidArgument(
           "Transaction name length must be between 1 and 512 chars.");
     } else {
       name_ = name;
-      txn_db_impl_->RegisterTransaction(this);
+      s = txn_db_impl_->RegisterTransaction(this);
+      if (!s.ok()) {
+        name_.clear();
+      }
     }
   } else {
     s = Status::InvalidArgument("Transaction is beyond state for naming.");
diff --git a/utilities/transactions/pessimistic_transaction_db.cc b/utilities/transactions/pessimistic_transaction_db.cc
index 7aca2bb523..ea38e17eea 100644
--- a/utilities/transactions/pessimistic_transaction_db.cc
+++ b/utilities/transactions/pessimistic_transaction_db.cc
@@ -723,6 +723,11 @@ void PessimisticTransactionDB::ReinitializeTransaction(
 Transaction* PessimisticTransactionDB::GetTransactionByName(
     const TransactionName& name) {
   std::lock_guard<std::mutex> lock(name_map_mutex_);
+  return GetTransactionByNameLocked(name);
+}
+
+Transaction* PessimisticTransactionDB::GetTransactionByNameLocked(
+    const TransactionName& name) {
   auto it = transactions_.find(name);
   if (it == transactions_.end()) {
     return nullptr;
@@ -755,13 +760,15 @@ void PessimisticTransactionDB::SetDeadlockInfoBufferSize(uint32_t target_size) {
   lock_manager_->Resize(target_size);
 }
 
-void PessimisticTransactionDB::RegisterTransaction(Transaction* txn) {
+Status PessimisticTransactionDB::RegisterTransaction(Transaction* txn) {
   assert(txn);
   assert(txn->GetName().length() > 0);
-  assert(GetTransactionByName(txn->GetName()) == nullptr);
   assert(txn->GetState() == Transaction::STARTED);
   std::lock_guard<std::mutex> lock(name_map_mutex_);
-  transactions_[txn->GetName()] = txn;
+  if (!transactions_.insert({txn->GetName(), txn}).second) {
+    return Status::InvalidArgument("Duplicate txn name " + txn->GetName());
+  }
+  return Status::OK();
 }
 
 void PessimisticTransactionDB::UnregisterTransaction(Transaction* txn) {
diff --git a/utilities/transactions/pessimistic_transaction_db.h b/utilities/transactions/pessimistic_transaction_db.h
index 77670e7d4a..bec29182ab 100644
--- a/utilities/transactions/pessimistic_transaction_db.h
+++ b/utilities/transactions/pessimistic_transaction_db.h
@@ -173,7 +173,7 @@ class PessimisticTransactionDB : public TransactionDB {
 
   Transaction* GetTransactionByName(const TransactionName& name) override;
 
-  void RegisterTransaction(Transaction* txn);
+  Status RegisterTransaction(Transaction* txn);
   void UnregisterTransaction(Transaction* txn);
 
   // not thread safe. current use case is during recovery (single thread)
@@ -239,6 +239,7 @@ class PessimisticTransactionDB : public TransactionDB {
   friend class WriteUnpreparedTransactionTest_MarkLogWithPrepSection_Test;
 
   Transaction* BeginInternalTransaction(const WriteOptions& options);
+  Transaction* GetTransactionByNameLocked(const TransactionName& name);
 
   std::shared_ptr<LockManager> lock_manager_;