Apa first reached the summit of Mount Everest on his fourth attempt, on May 10, 1990, with a New Zealand team led by climber Rob Hall along with Peter Hillary, son of Edmund Hillary. He then began his career as Sirdar, or chief Sherpa, for many high altitude expeditions. Except for 1996 and 2001, he reached the summit every year between 1990 and 2011; all but three times have been in May. In 1992 he reached the summit twice.