His biggest success came in 1989 when he won the European Indoor Championship's 60 meter dash. In 1987 and 1989 he reached the World Championship semi-finals (1987 outdoors at 100 & 200m) (1989 indoors at 60m). He participated in the 1988 Summer Olympics reaching the quarter-finals of the 100 and 200 metres. Berger caused two false starts during a 100-meter first round qualifying heat at the 1992 Summer Olympics and was disqualified. He went on to reach the quarter-finals of the 200m and the final of the 4 × 100 m relay. He still holds the Austrian 100m dash record (10.15s, 1988).
He was Austrian 100/200 metre champion thirteen times. Berger also won the Austrian 60/200 metre indoor championships on six occasions. He competed at the European championships in Stuttgart 1986 in the 100 metres, but did not advance pass the semi-final.