Wildgruber won the bronze medal in the downhill at the 1977 European Junior Championships in Kranjska Gora . He started in the World Cup in 1976, but initially failed to achieve success. The main reason for this was the early death of his father and brother. He took over his parents' farm and worked as a farmer in the summer , so that he had to neglect the preparation for the season on the glaciers. The Sporthilfe also withdrew the financial support for a temporary worker.
Wildgruber won his first World Cup points on December 14, 1980 as 15th of the combination in Madonna di Campiglio . A little more than two years later, the first place in the top ten followed in the downhill from Sarajevo . The departure of the 1984 Winter Olympics in the same place he finished in seventh place. That was also the best ranking of the entire German men's team.
1984/85 was Wildgruber's most successful season, and he was particularly convincing towards the end of the season. On March 2, 1985, he finished second in Furano and achieved the best result of his career, a week later followed by third place in Aspen . In December 1985, he achieved another podium finish on the Saslong in Val Gardena .
In the descent of the 1987 World Championship in Crans-Montana , Wildgruber finished in tenth place. Shortly before the 1988 Olympics, he suffered a concussion in a fall. Although he recovered in time, he was still not nominated. After missing qualification for the 1989 World Cup, Wildgruber resigned. Since then he has been working as a farmer again.