Christodoulou was an important member of the senior men's Greek national team that won the gold medal at the 1987 EuroBasket and the silver medal at the 1989 EuroBasket. Christodoulou was also a member of the Greek national team that finished in 4th place at the 1994 FIBA World Championship. He also played at the 1986 FIBA World Championship, the 1990 FIBA World Championship, the 1993 EuroBasket, the 1995 EuroBasket, the 1997 EuroBasket, and at the 1996 Summer Olympic Games.