Lancia continued to use the HF integrale 16v throughout the 1990 season.

Markku Alen left the team after nearly fifteen years whilst Juha Kankkunen rejoined, alongside Biasion and Auriol. The French driver won the Monte Carlo Rally and Tour de Corse whilst Biasion won in Portugal, giving Lancia an advantage it retained until the end of the season, by which time it had taken six wins and won the manufacturers' title for the fourth time. However, the wins were shared between the team's three drivers, and in the drivers’ championship race Sainz, driving a Toyota Celica GT-Four ST165, secured a string of mid-season victories that gave him the title. It was first time since 1986 that Lancia had not won both drivers’ and manufacturers’ championships.