A mother who was attending to her baby in her car in Douglas had her mobile phone stolen from the child's empty pram parked at the side.
Isle of Man Police said the woman was "very distressed" by the theft, which took place outside The Welbeck Hotel, Mona Drive, at 1530 BST.
A man was seen approaching the pram and taking the Samsung phone before making off towards the promenade.
Police have appealed for witnesses to get in touch.
An Isle of Man Police spokesman said: "This theft has left the aggrieved feeling very distressed and upset as she was in her car alongside the pram attending to her baby at the time of the offence.
"I would urge anyone with any information as to the identity of this male to contact the police or Crimestoppers."