Purpose: The study adopted a randomized controlled trial to compare the effect of culturally compatible psychosocial interventions on multiple aspects of quality of life (QoL) for family caregivers of lung cancer patients. Methods: 157 Chinese informal caregivers of lung cancer patients were recruited together with the family members for whom they were providing care, and randomly assigned to either integrative body-mind-spirit intervention (I-BMS) or cognitive behavioral therapy (CBT). Patient-caregiver dyads attended the same arm of intervention in separate groups for 8 weeks. Assessments of generic QoL, anxiety, depression, perceived stress, insomnia, and caregiving burden were measured before intervention (T0), within 1-week (T1), 8-week (T2), and 16-week (T3) post-intervention. Results: Adopting the intention-to-treat analysis, family caregivers in receipt of both I-BMS and CBT exhibited a statistically significant improvement in generic QoL immediately following intervention and at follow-up assessments, with moderate effect size. Improvement of insomnia was found at T1 for both modes, which deteriorated at follow-up; both modes reduced anxiety and perceived stress at follow-up. No intervention effect was observed in depression and domains of caregiving burden. There was no significant interaction effect between intervention type and time. No main or interaction effect between sample background variables and intervention type was found to predict symptomatic changes at T1 and T3. Conclusions: Culturally attuned I-BMS and CBT exhibited equivalent effectiveness in improving psychological distress and generic QoL for family caregivers of lung cancer patients. To improve the evaluation of outcomes, future study could benefit from incorporating a usual care control.