<p>Existing research examining the relationship between religiosity and organ donation has produced inconsistent results. To address this ambiguity, the current study adopts meta-analysis to synthesize findings from 18 studies examining associations between religiosity and two categories of organ donation variables: psychological indicators (attitudes toward donation and intentions to register) and registration outcomes (actual donor registration status). Two separate random-effects meta-analyses were conducted, indicating that religiosity was not significantly associated with psychological outcomes (k = 15), yet demonstrated a significant negative impact on actual organ donor registration behaviors (k = 5). A random-effects meta-regression further assessed potential moderators including age, gender, country context, and data collection type, none of which meaningfully explained variability in the observed effect sizes. Evidence of publication bias was identified, suggesting the current results may underestimate the negative magnitude of religiosity’s impact on organ donation. Our findings underscore the attitude-registration discrepancy, highlighting the importance of clergy clearly communicating guidance regarding organ donation. Further theoretical and practical implications are discussed.</p>