The family relationships of patients with anorexia nervosa (AN) have been extensively studied over recent years. However, using case-control designs with unrelated controls is subject to various cultural and familial biases. Studying subjective differential perceptions of family relationships in sister-pairs discordant for the disorder may overcome some of these limitations. The aim of the present study was therefore, to investigate subjective perceptions of family environments in a clinically ill sample of female adolescent patients with acute AN and in their healthy sisters using the Subjective Family Image Test. We found significantly lower perceived individual autonomy and higher perceived cohesion in patients compared with their sisters but no difference in perceived emotional connectedness. Lower perceived individual autonomy of the ill children resulted mainly from their relationships with mothers but also in part from their relationships with fathers. This observed pattern might contribute to the maintenance of the disorder and should be addressed in individual and family interventions.