Todorov made in 1986 in Copenhagen by winning the European Junior Championships in flyweight attention. He then took part in the following year at the Junior World Championships in Havana, left there, however, in the quarter- finals with a narrow point of defeat. In 1988 he took up at the Seoul Olympics in the flyweight and failed there in the quarterfinals at the local heroes and later gold medalist Kim Kwang -sun.
He then went on in the bantamweight and was founded in 1989 in Athens, European Champion and Vice World Champion in Moscow. The Goodwill Games 1990, he took a second place. In 1991 he defended his European title in Gothenburg, including a semi-final victory over Andreas Tews, and won his first World Cup in Sydney. He suggested there in the finals the Cuban Enrique Carrión, he had two years earlier still inferior.
At the Olympic Games in 1992 Todorov again lost in the quarter- final against the North Koreans Lee Gwang -sik 15 to 16 Erwechselte then again the weight class and boxed at featherweight. In this weight class arrive in 1993 in Bursa another European Championship, and in 1993 in Tampere ( 11:6 points victory over the Cubans Enrique Carrión ) and in Berlin in 1995, his second and third world title.
In 1996 he lost his first fight in a European Championship, when he joined the antretenden for Russia Georgians Ramaz Paliani lost the final. He then took part in his third Olympic Games and won the silver medal there, after he had beaten controversial in the semifinals with 10 to 9 Floyd Mayweather. In the final he surprisingly lost against the Thais Somluck Kamsing.
Serafim Todorov also fought in the German Bundesliga. He was defeated, antretend for the Schwerin SC, including in December 1994 against Falk huste from Frankfurt (Oder ) on points ( 8:17 ).
In 1998 he began a half-hearted pro career in which he finished after five wins and one defeat.