Purpose: There is evidence to support that meaning-centered group psychotherapy for cancer survivors (MCGP-CS) is an effective intervention for improving personal meaning and psychological well-being, as well as reducing psychological distress. In order to investigate which subpopulations MCGP-CS specifically benefits, this explorative study aims to analyze potential sociodemographic, clinical, and psychosocial factors that may moderate the effects. Methods: Cancer survivors (N = 114) were randomly assigned to MCGP-CS, or care as usual (CAU). Potential moderators included age, sex, relationship, education, employment, religion, cancer type, tumor stage, cancer treatment, time since treatment, anxiety, depression, other negative life events, and previous psychological treatment. Outcome measures were the Personal Meaning Profile (PMP), Scales of Psychological Well-Being (SPWB), and the Hospital Anxiety and Depression Scale (HADS). Assessment took place at baseline, post-intervention (short-term), and 3- and 6-month follow-ups (long-term). For each moderator, separate short-term and long-term linear mixed models were built. Results: Short-term effect of MCGP-CS was moderated by (male) sex (on HADS-D; F(1,98) = 6.1, p = .015) and (a high level of) depressive symptoms at baseline (on SPWB; F(1,93) = 5.7, p = .019). Long-term effect of MCGP-CS was moderated by (not having received) previous psychological treatment (on HADS-total; F(3253) = 3.4, p = .017). Conclusions: Most sociodemographic and clinical characteristics do not appear to moderate the positive effect of MCGP-CS on personal meaning. However, MCGP-CS appears to reduce depressive symptoms, particularly in males, and to improve purpose in life of survivors with depressive symptoms. In the long-term, MCGP-CS appears to reduce psychological distress in survivors who had not received psychological treatment in the past year. Trial registration: NTR3571.