Epidemiological studies have highlighted a strong male bias in autism spectrum disorder (ASD), however few studies have examined gender differences in autism symptoms, and available findings are inconsistent. The aim of the present study is to investigate the longitudinal gender differences in developmental profiles of 30 female and 30 male age-matched preschool children with ASD. All the children underwent a comprehensive evaluation at T0 and at T1. Our results have shown no significant interaction between time and gender for predicting autism symptoms, developmental quotient, parental stress, children’s adaptive skills and behavior problems. Shedding light on the developmental trajectories in ASD could help clinicians to recognize children with ASD at an earlier age and contribute to the development of appropriate treatments.