Six-month follow-up results from a trial investigating the effects of Radically Open Dialectical Behavior Therapy (RO-DBT) in individuals with anorexia nervosa are presented. Participants (N = 23; median age 20 years; 96% female) completed a 32-week RO-DBT intervention. Repeated Measures ANOVAs were used to examine changes over time. The primary outcome was eating disorder psychopathology. Exploratory outcomes were BMI, obsessive-compulsive personality traits, emotion regulation, work function and treatment utilization. Statistically significant reductions in eating disorder psychopathology, albeit mean EDE-Q scores remained above the established clinical cutoff, and increases in BMI from pre-treatment to post-treatment were sustained at 6-month follow-up with significant effects of time. A statistically significant reduction in the doggedness scale in FFOCI-SF was observed between pre-treatment and the 6-month follow-up. Findings suggest that participation in RO-DBT is associated with sustained improvements in eating disorder symptoms and BMI for individuals with anorexia nervosa, suggesting that RO-DBT is a treatment alternative for anorexia nervosa that warrants further evaluation in controlled trials.