Andrzej Krzeptowski I was the son of a guide and courier in the Tatra mountains. In 1922, he won his first national titles in the 18 km cross-country and Nordic combined, and also placed second in jumping. The following year, Krzeptowski was Polish champion in Nordic combined, ski jumping and slalom. In 1924, he won his sixth national title in the 18 km cross-country and was sent to the Winter Olympics in Chamonix. In 1926, his next Polish Championships came in combination and jumping. At the 1927 World Championships he placed ninth in Nordic combined and 18th in jumping. In his second Winter Olympics in St. Moritz, he was selected as flagbearer of the Polish team and competed only in jumping. In 1929, his last major achievements were the national title in the 4x10 km cross-country relay and the participation in the jumping event at the 1929 Worlds in his hometown Zakopane, where he finished 27th. His cousin Andrzej Krzeptowski II was also a skier and 1928 Winter Olympian.
During the occupation in World War II, he actively collaborated with the Germans as a member of a minority called Goralenvolk, and received privileges by the Germans. He was the chairman of the branch in Zakopane, where he lived and ran a big hardware store. Some, however claimed that he also supported the Polish resistance. Nevertheless, he was sentenced to death by an army court, but the penalty was not carried out. After the liberation by the Red Army, the leaders of the Goralenvolk were detained and indicted for war crimes. He died under dubious circumstances. According to a document, he killed himself taking poison and died in the hospital, where he was taken from prison. His family got the news of his death only in the 1950s.