IntroductionGirls with classical congenital adrenal hyperplasia (CAH) are exposed to excess fetal adrenal androgens in-utero, and often born with masculinised genitalia. They are conventionally reared as females, but show more “boyish” gender-role behaviour (GRB) and gender-identity (GI) issues in childhood and adolescence. Male-rearing is also reported mainly due to delayed treatment and/or socio-cultural factors. We compared GRB/GI in girls with CAH with healthy age matched children, and explored for associations with socio-demographic and diagnosis/treatment related factors.MethodsGRB and GI were assessed using the Gender Identity Questionnaire for children (GIQC) in 27 girls with classical CAH at a specialised clinic, and compared with 50 age-matched healthy controls, with exploratory-analysis based on socio-demographic and diagnosis/treatment-related factors.ResultsGirls with CAH had lower total GIQC scores compared to healthy children (3.29 vs. 4.04, p = < 0.001) with lower GRB score (3.39 vs. 4.23, p < 0.001), and tendency for lower GI score (3.19 vs. 3.5, p = 0.08). Exploratory analysis showed no differences based on diagnosis/treatment factors including age, degree of virilisation at diagnosis and surgical procedures. and only subtle changes based on ethnicity and maternal education.Discussion/conclusionGirls with CAH managed at a specialised centre showed more masculinised GRB and tendency for ambiguous GI, which did not vary upon diagnosis/treatment related factors, suggesting that prenatal androgen exposure was the likely contributor. Clinicians should be vigilant about the increased risk of gender-related problems in girls with CAH, irrespective of sociocultural background and despite early treatment.