INTRODUCTION: Organ transplantation is a therapy which depends on society for its development. The objectives here are: 1) to understand the structure of public opinion towards organ donation in the population aged over 15 years of age in our Community; 2) to analyse the psychosocial variables which affect this opinion and 3) to define the population profiles on this matter. MATERIALS AND METHODS: Random sample (n = 2.000) stratified for age, sex and geographical location (error for 95.5%, e +/- 2.24) to whom we apply a questionnaire about the psychosocial aspects of organ donation. Descriptive statistics, Student's t-test, Chi-squared test and logistical regression analysis. RESULTS: 63% have a favourable attitude towards organ donation, of which 11% have a donor's card. A statistical association has been observed between favourable public opinion and different psychosocial variables (p < 0.05), with some independent variables persisting in the multivariate analysis such as age, level of education (OR = 1.78), information given by family members (OR = 1.62), health workers (OR = 2.01) and talks in educational centres (OR = 2.13); previous experience with donation and transplantation (OR = 2.02), knowledge of the concept of brain death (OR = 1.4); partner's favourable opinion towards donation (OR = 2.6), being a blood donor (OR = 3), taking part in prosocial activities (OR = 1.6) and attitude towards incineration of the cadaver after death (OR = 1.8). CONCLUSIONS: The profile of a person who is against donation is of a man or woman, > 50 years of age, with primary studies or below, with no previous experience of the matter, who does not understand the concept of brain death nor their partner's opinion towards donation, who has not found out any information about donation through specialised forums, with an unfavourable opinion towards blood donation or pro-social activities and who is fearful of manipulation of the cadaver after death.