Research on the effects of nursery school attendance still presents divergent results: a possible explanation is that the effects of child care on development outcomes can be modulated by individual characteristics, such as gender or temperament. In the present study, gender differences in nursery adaptation (evaluated by social skills and behavioural problems) have been explored: participants are 525 toddlers, attending 32 nursery schools with similar levels of quality in a large city in northern Italy. Associations with age of enrolment, hours of attendance and child temperament have also been analyzed. Results indicate that males are more vulnerable than females: spending more time in the nursery increases the risk of behavioural problems in males but not in female, and an early enrolment (under one year of age) results in greater relational skills only for females. Difficult temperamental traits are also associated with behavioural problems with gender-specific aspects. Educational implications are discussed.