The Swiss Football Association (ASF/SFV) had 28 member clubs at this time and these were divided into two divisions of 14 teams each.
The teams played a double round-robin to decide their table positions.
The top tier (NLA) was contested by the top 12 teams from the previous season and the two newly promoted teams FC Zürich and FC La Chaux-de-Fonds.
The last two teams in the league table at the end of the season were to be relegated.
Urania Genève Sport and FC Chiasso finished the season level on points in joint first position and both achieved promotion to 1948–49 Nationalliga A.