For the 1991 Rugby World Cup, 16 nations participated in the finals tournament, half of which came through qualifying matches, and the other were granted automatic entry as they were quarter-finalists at the 1987 Rugby World Cup.
In qualification for the 1991 Rugby World Cup, Asia and Oceania were combined.
The qualifying round-robin tournament was played in Japan in April 1990.
Three nations from the Americas competed in qualifying matches for the 1991 Rugby World Cup.
Because the Americas region had three places at the 1991 Rugby World Cup, all three participating countries from the Americas—Argentina, Canada and the United States—qualified for the finals tournament, with the qualifying tournament deciding to which pool each team would be allocated at the finals.