Objectives: The main objective of this paper was to examine the cost-utility of attachment-based compassion therapy (ABCT) compared to Mindfulness-Based Stress Reduction (MBSR) and treatment-as-usual (TAU) on patients with depressive and/or anxious disorder, or adjustment disorder with depressive and/or anxious symptomatology in terms of effects on quality-adjusted life years (QALYs) as well as healthcare costs from a public healthcare system perspective.Method: A 6-month randomized controlled trial was conducted. Ninety Spanish patients with mental disorders (depressive, anxious, or adjustment disorders) received 8 weekly group sessions of TAU + ABCT, TAU + MBSR, or TAU alone. Data collection took place at pre- and 6-month follow-up. Cost-utility of the two treatment groups (ABCT vs MBSR vs TAU) was compared by examining treatment outcomes in terms of QALYs (obtained with the EQ-5D-3L) and healthcare costs (data about service use obtained with the Client Service Receipt Inventory).Results: Both MBSR and ABCT were more efficient than TAU alone, although the results did not reach statistical significance. Compared to ABCT, MBSR produced an increase both in terms of costs (€53.69, 95% CI [− 571.27 to 513.14]) and effects (0.004 QALYs, 95% CI [− 0.031 to 0.049]); ICUR = €13,422.50/QALY). Both interventions significantly reduced the number of visits to general practice compared to TAU.Conclusions: This study has contributed to the evidence base of mindfulness- and compassion-based programs and provided promising information about the cost-utility of MBSR for patients with emotional disorders. However, the small sample size and short follow-up period limit the generalizability of the findings.Preregistration: Clinicaltrials.gov; NCT03425487.