A method and system for detecting and isolating memory leak in RAID controllers utilizing sequence numbers. The system monitors whether the count of un-freed memory blocks for a sequence number (SN) zone (after a start-of-day SOD operation, but smaller than the current sequence number zone) is not eventually decremented to zero. The memory leak can be detected when un-freed memory blocks exist and follow a similar pattern with respect to all other adjacent SN zones. The detected memory leak can be isolated utilizing shell commands, task information, caller information, sequence number, memory allocation size and a pointer to the next allocated memory block.