This study assessed the relationship between acceptance-based constructs and quality of life (QOL) among patients with an eating disorder, as well as whether an acceptance-based treatment group could improve QOL. Patients ( 105) at a residential treatment center received treatment as usual (TAU) or TAU plus twice-weekly acceptance and commitment therapy groups (TAU+ACT), and completed assessments at admission and discharge. Higher scores on several acceptance-related constructs at admission were associated with better psychological QOL, and pre- to post-treatment improvements in the ability to defuse from distressing internal experiences were associated with improved QOL. However, no differences in pre- to post-treatment changes in QOL were observed between treatment conditions. These results suggest that while some acceptance-related variables (e.g. defusion, impulse control, access to emotion regulation skills) may contribute to QOL, ACT does not appear to incrementally improve these variables or QOL beyond standard treatment programs. Additional research is needed to evaluate whether ACT may confer greater benefit for improving QOL in an outpatient setting where patients have more opportunity to utilize ACT skills, or when a stronger dose of treatment is administered.