A total of 28 AFC teams entered the competition. However, Chinese Taipei were assigned to the Oceanian zone instead. The Asian zone was allocated 2 places (out of 24) in the final tournament. Asia's automatic qualifying berths were taken by Iraq and Korea Republic
The 27 teams were divided into 2 zones, based on geographical considerations. Zone A had 13 teams (teams from West Asia) and Zone B had 14 teams (teams from East Asia). There would be three rounds of play in each zone:
First Round: The teams were divided into 4 groups of 3 or 4 teams each. The teams played against each other on a home-and-away basis. The group winners would advance to the Second Round.
Second Round: The 4 teams in each zone were paired up to play knockout matches on a home-and-away basis. The winners would advance to the Final Round.
Final Round: The 2 teams in each zone played against each other on a home-and-away basis. The winners would qualify for the 1986 FIFA World Cup.
Due to wars their countries were involved in, Iran, Iraq and Lebanon had to play all their home matches on neutral ground or away.