IntroductionThe African population is one of the largest immigrant groups in Europe. Religious beliefs are deeply rooted in most African societies and condition their attitude toward organ donation. ObjectiveWe sought to analyze the influence of Catholicism in the attitude toward organ donation among Africans residing in Spain. Materials and methodsStudy participants were born in Africa and were residents in Spain. Data were obtained from the database of the International Donor Collaborative Project, which includes a sample of the population for 15 years, stratified by those who were born in Africa, as well as age and sex. The instrument used was a validated attitude questionnaire toward living kidney donation (PCID-DTO-Ríos). ResultsOf the population under study, 13% are Catholics (n = 475) and 80% (n = 2896) are Muslims. The favorable attitude toward the donation of cadaver organs is 53.7% (n = 255) among Catholics compared with 25.6% (n = 742) among Muslims (P < .001). On the contrary, 17.7% of Catholics have an unfavorable opinion (n = 84), while 45.5% (n = 1280) of Muslims have an unfavorable opinion; 28.6% of Catholics and 29.2% of Muslims are undecided.In addition, among Catholics who believe that their doctrine accepts organ donation and transplantation, 70.6% (n = 132) are in favor of donating a corpse compared to those who believe that Catholic doctrine is against (P < .001 ), with only 35% (n = 7) in favor of the donation. ConclusionsAfricans who have converted to Catholicism have a more favorable attitude toward donating their own organs than those who continue in Islam.