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 1954–55 season and the two newly promoted teams Urania Genève Sport and FC Schaffhausen.
The champions would qualify for the 1956–57 European Cup and the last two teams in the league table at the end of the season were to be relegated.
The second-tier (NLB) was contested by the two teams that had been relegated from the NLA at the end of the last season, these were FC Thun and FC Luzern, the ten teams that had been in third to twelfth position last season and the two newly promoted teams FC Rapid Lugano and FC Lengnau.