A study about the incidence of malignant melanoma in Puerto Rico during the calendar year 1996 was carried out compiling the information submitted by pathological reports to the Puerto Rico Cancer Registry and identifying similar reports at other pathology laboratories. A total of 107 new cases were documented in 1996, resulting in an incidence of 3.03 (+/- 17.9) per 100,000 persons for that particular year. The age of the patients fluctuated between 19 and 88 years with a mean of 61.3 years, most of them being between 50 and 80 years. More than half of the cases (54.2%) were located in the head and neck, and the extremities. Thickness measurement of the neoplasm was reported in only 42% of the cases. In 60% of those cases in which the tumor thickness was reported, it was found to be less than 1.49 mm. Previous data in Puerto Rico from the years 1981 to 1986 had shown a tendency to an increase in the incidence of melanoma per 100,000 inhabitants rising 1.20 to 1.52 respectively. The present study reflects a continuation of the same pattern, with a two-fold increase in the last 10 years (from 1.52 to 3.03).