A method, system and computer program product for detecting sensitive personal information in a storage device. A block delta list containing a list of changed blocks in the storage device is processed. After identifying the changed blocks from the block delta list, a search is performed on those identified changed blocks for sensitive personal information using a character scanning technique. After identifying a changed block deemed to contain sensitive personal information, the changed block is translated from the block level to the file level using a hierarchical reverse mapping technique. By only analyzing the changed blocks to determine if they contain sensitive personal information, a lesser quantity of blocks needs to be processed in order to detect sensitive personal information in the storage device in near real-time. In this manner, sensitive personal information is detected in the storage device using fewer computing resources in a shorter amount of time.