PURPOSE: To study the prevalence of multiple neoplasms in patients affected by uveal melanoma in Spain and to relate these with survival. METHOD: We carried out a longitudinal prospective study of the prevalence of multiple neoplasms in patients diagnosed to have a uveal melanoma during the years 1984-2005. The data has been analysed for the following variables: age, sex, date of diagnosis, affected eye, origin and tumoral size, classification according to COMS (Collaborative Ocular Melanoma Study), time of follow-up, presence of other neoplasms, current clinical state, date and cause of death. RESULTS: Three hundred and five patients affected by uveal melanoma have been studied in the Ocular Oncology Unit of our institution; 24 patients (7.9%) had evidence in their medical reports of one or more additional neoplasms. Excluding cutaneous neoplasms originating in basal cells, this number reduced to 22 patients (7.2%). We did not find any statistically significant differences among the presentation age, sex or localization of the melanoma (ciliary body or choroid) and the presence or absence of a second neoplasm. When we analysed the proportion of patients with metastatic disease (both alive and dead) who presented with a second neoplasm (40.9%), we found a statistically significant relationship between these variables (Chi-square test, p=0.004). CONCLUSIONS: We have observed a percentage of second neoplasms similar to that described in other international studies. We did not find a larger proportion with a second neoplasm according to the sex, age, or tumoral localization, nor did we observe a higher frequency of any particular second neoplasm. We have defined a relationship between metastasic uveal melanoma, and the development of a second neoplasm, which clearly indicates a need for increased systemic follow-up in such patients.