The Serie B 1951–52 was the twentieth tournament of this competition played in Italy since its creation.
Monza, Valdagno, Piombino and Stabia had been promoted from Serie C, while Roma and Genoa had been relegated from Serie A.
A provisional fifth relegation was added to reduce the league.
FIGC’s President Ottorino Barassi imposed a playoff between the second club in B and the seventeenth in A to reduce the Serie A.
The 3 last-placed teams in Serie A were guaranteed relegation.