He trained with Andy Hug from 1992 to 2000. Majstorović"s karate record is at 45 wins and six losses out of 51 fights. His K-1 record is at 69 wins and 22 losses out of 90 fights.
In 2009, he registered Petar Majstorovic K Gym as a private business in Bern.
2004 he declined a doping test in Switzerland.
2013 Fight Night European Heavyweight kickboxing champion 2008 World Full Contact Association (WFCA) World Super Heavyweight kickboxing champion 2008 WPKC World Heavyweight champion +95 kg 2006 K-1 Fighting Network Prague Round "07 runner up 2003 K-1 Spain Grand Prix in Barcelona runner up 2002 K-1 World Grand Prix Preliminary Croatia champion 2001 K-1 World Grand Prix Preliminary Germany Champion 2001 W.K.N. World Kickboxing champion 2001 K-1 World Grand Prix Preliminary Germany champion 2000 WKN Intercontinental Thai boxing champion 1998 WKA European Kickboxing Heavyweight champion 1996 Switzerland Seidokarate Open champion.
