This study represented an exploration of possible protective factors in the lives of adolescents whose sisters suffer from anorexia nervosa. In examining the 16 patients, ages 12-21, and their 16 siblings free of eating disorders within three years of age of the patient, this research has attempted to understand the dynamics of anorexia nervosa as it related to the sisters who comprised the comparison group. The purpose of this research was to investigate some mental health factors of female adolescent siblings of patients with anorexia nervosa who themselves have never exhibited eating disorders, to identify those psychosocial factors that are shared by anorectics with their sisters who are free of eating disorders, and to identify those psychosocial factors that separate the two groups. Four aims and a series of nine hypotheses were formulated and the two groups compared on factors of affective psychopathology, perceived social networks, anxiety disorders, locus of control, parents' assessment of child's competence, child's assessment of the same, and perceived family cohesiveness and adaptability. Relationship among these variables was studied within the different samples, and a parental assessment of both girls was provided by their mothers. Findings revealed that the anorectic patients had a restricted social network, manifested a somewhat more external locus of control, and had a high prevalence of affective disorders, as compared to their siblings. The siblings perceived themselves as more competent in general and social functioning. There was no difference between these two groups on perceived cognitive and physical functioning or their perception of family cohesion and adaptability. The mothers perceived the anorectic daughters a s less socially competent but rated both daughters equally competent on cognitive , physical, and general functioning. The correlation between parental perception of competence and self-report of their daughter was slightly higher in the anorectic patients than in their siblings . Findings indicate that the psychosocial correlates o f anorexia nervosa are multivaried and do not necessarily fit the prevailing stereotypes in the literature on this disorder.