A consecutive series of school age children (7 to 16 years) with emotional disorders (N = 100) were compared with a series of community controls (N = 100) matched for age, sex and social class for the quality of their friendships. A semi-structured interview was developed to measure the quality of friendship for this purpose. Significantly more (48%) children with emotional disorder were likely to be rated as experiencing moderate to poor friendships in the 12 months prior to the onset of symptoms than were controls (16%) in the 12 months prior to interview. Prepubertal children with moderate to poor friendship patterns were classified as either predominantly anxious or depressed. Postpubertal children with moderate to poor friendships patterns were, in contrast, predominantly anxious. These findings suggest that puberty denotes a point of change for the impact of friendship deficits on the psychopathology of emotional disorder. There were no sex differences in the clinical classification of children with moderate or poor friendship patterns.