SUBARU debuted the Legacy in the WRC in 1990. Problems in obtaining homologation prevented SUBARU from entering the Legacy until the fourth round of the season, the Safari Rally. Also competing in this rally was SUBARU Rally Team Japan, a team that had been entering WRC events since the 1980 release of the SUBARU Leone, and was led by Noriyuki Koseki. The Legacy was therefore represented by no less than 6 vehicles at its debut WRC event: five in Group A, and one in Group N.
Legacy's debut event proved a partial success. While Alen gained an early lead over competitors with a best time in SS1, three of the five Legacy entries in Group A retired in the first leg. Another Legacy veered off the course in the third leg, and ultimately only one of the Group A entries completed the rally, finishing in sixth place overall. The Group N Legacy finished with ease, placing first in its class. It was the first Group N vehicle ever to finish the Safari Rally.
SUBARU wasn't able to garner the results it had hoped for in the remaining rounds of the Legacy's WRC debut year. But throughout the season, the Legacy was able to give brief glimpses of its high potential, occasionally outperforming the Lancia Delta and the Toyota Celica, which were considered the fastest cars at the time.