In 1994, his first year competing as a senior, Melissanidis enjoyed success on the world stage. He won the floor exercise title at the 1994 European Championships in Prague. At the 1994 World Championships he tied with Great Britain's Neil Thomas for the silver medal on floor. With this win, Melissanidis became the first Greek gymnast, male or female, to medal at the World Championships. Melissanidis' fortunes changed after 1994: at the 1995 and 1996 Worlds he did not qualify for a single event final.