Burglars broke into two businesses on Streatham High Road at the weekend but failed to make off with any loot.
One would-be thief targeted the Card Factory shortly after 5.45pm on Saturday, smashing a window to enter the shop but running away before stealing anything.
Another person kicked in the front door of I Love Coffee at about 4am on Sunday, but was not able to get inside.
Police are not linking the two incidents but continue to investigate both separately. No arrests have been made.
Anyone with information should call 020 8721 3513 or speak to Crimestoppers anonymously on 0800 555 111.