He started his career in Iraklis, debuting in 18 January 1981 when Iraklis was participating in the Beta Ethniki. In Iraklis's team he played seven seasons before heading to Olympiacos. In 1992 he joined Aris Thessaloniki F.C., the city rivals of Iraklis, where he played until rejoining Iraklis in the 1996–97 season.
His three appearances at the 1994 World Cup rounded off his national team career, which lasted from 1982 to 1994, giving him 67 caps and 1 international goal (9 January 1985, against Israel). He retired from professional football in 1999.
During the 2002–2003 period he was the assistant coach of Ivan Jovanovic in Iraklis, as well as the next period, assisting head coach Sergio Markarián. After Markarián resigned, Kofidis took in charge as the head coach. The next year, with Kofidis taking the reins, was hugely successful as "The Old One", against all expectations, finished 4th in the 2005–2006Alpha Ethniki championship, and qualified for the UEFA Cup. During the summer, however, many key players were sold as the team was in heavy debt, and the following year was anything but successful. After a string of 10 league matches without a win, and an early exit from the UEFA Cup against Polish team Wisła Kraków, Kofidis resigned. In January 2007 he became head coach in Skoda Xanthi following Takis Lemonis's resignation, but soon left the job. On 30 October 2009 Iraklis F.C. club officials have sacked coach Oleg Protasov to replace him with Kofidis.