One of thirteen siblings, Johann Passler worked as a policeman in his native Antholz, and joined the Italian Carabinieri Sports Centre in the early 1980s. Passler competed in four Winter Olympics between 1984-94, with his best Games coming at Calgary in 1988, with bronze medals in the 20 km and relay. He débuted at the World Championships in 1983 and won his only individual World medal with a bronze in the 1985 sprint, adding another bronze in the 1986 relay. In 1990 and in 1993, the Italian relay team of Passler, Pieralberto Carrara, Wilfried Pallhuber, and Andreas Zingerle, won World gold. Between 1985 and 1995 he raced regularly in the World Cup, with seven podiums and three wins (one each in 1988, 1989, 1993), and placing third in the 1988 overall standings. At Italian Championships he won 15 medals – six gold, six silver, and three bronze between 1982-95, with two titles each in his preferred sprint and the 20 km. Passler competed through 1996, when he won the European Biathlon Cup.