The aim of this case series was to examine engagement in and outcomes of family-based treatment (FBT) for adolescents with DSM-5 atypical AN, that is, adolescents who were not underweight at presentation. Consecutive referrals for FBT of adolescents with atypical AN to a specialist child and adolescent eating disorder program were examined. Engagement in treatment (i.e., dose of treatment, completion rate), and changes in psychological symptomatology (i.e., eating disorder symptoms, depressive symptoms, self-esteem, obsessive compulsiveness), weight, and menstrual function were examined. The need for additional interventions (i.e., hospitalization and medication), and estimated remission rates were also examined. The sample comprised 42 adolescents aged 12-18 years (88% female). Engagement in FBT was high, with 83% completing at least half the treatment dose. There were significant decreases in eating disorder and depressive symptoms during FBT (p < .05) but no improvement in self-esteem. There was no significant change in percent of median BMI for age and gender for the sample as a whole (105 vs. 106%, p = .128). However, adolescents who were not admitted to hospital prior to FBT gained some weight (M = 3.4 kg) while those who were admitted did not gain weight during FBT (M = 0.2 kg, p < .01). The overall remission rate ranged from 38 to 52% depending on the criteria applied. FBT appears to be an effective treatment for adolescents with atypical AN. However, more research is needed into systematic adaptations of FBT and other treatments that could improve overall remission rates.