Police and the family of 20-year-old Andrew Quigley are becoming increasingly concerned for him after he failed to return home from a evening out on January 17.
Andrew was last seen in the Gallagh/Shantallow areas at around 2am on January 18.
A PSNI spokesman said: “Items belonging to Andrew, including a mobile phone, were found on the Foyle Bridge at around 7:40am on Saturday morning.”
Andrew is described as being about 6ft 2ins and of a medium build.
When last seen he was wearing blue jeans, a navy striped t-shirt and a black and purple jacket.
The PSNI spokesman added that the missing man also has “a distinctive celtic style tattoo on the back of his right forearm”.
Anyone who saw Andrew over the weekend, or knows of his whereabouts, is asked to contact Strand Road station on 0845 600 8000.