Within each group, the teams would play a double round-robin to decide their league position.
The four group winners and the four runners-up contested a play-off round to decide the five promotion slots.
Within each of these groups the teams contested another double round-robin.
The decider match for second group place was played on 29 June in Näfels FC Locarno win and are promoted to 1981–82 Nationalliga B.
The decider matches for fifth promotion place were played on 28 June and 1 July.