The general gender discourse has currently revealed gender gaps as early as at preschool age. To analyze developmental differences between boys and girls in Mecklenburg-Western Pomerania, n = 4,251 preschoolers aged 48-83 months were examined by means of the 'Dortmund Developmental Screening for Preschools 3-6' (DESK 3-6). Using the "sex-nonspecific" overall screening norms, sex differences were favoring females at all ages and in all areas of competence (0.18 = |d| = 0.82): fine and gross motor skills, language and cognition, and social development. The application of "sex-specific" norms, however, placed emphasis on diversity within groups instead of sex dichotomies, on the complexity of child development and the individuality of intervention needs: Sex differences were generally negligible, apart from few statistically significant, yet quantitatively small, effects (0.005 = |d| = 0.42). Consequently, competency-based, intersectional, individual-centred rather than sex-based strategies seem promising for preschool programs in northeastern Germany.