OBJECTIVES: : The demographic profile of Puerto Rico is changing; according the 2000 and 2010 Census of the Population, Puerto Rico has 3810,605 and 3,722,133 inhabitants, respectively. In this period the population of 65 years or older increased from 11.2% to 15%; the median age increased from 33.8 years in 2004 to 37.0 years in 2010. The extent to which these population changes affect cancer mortality is not known. The objective was: to assess the impact of changes in the demographic profile of Puerto Rico from 2000 until 2010 on melanoma and lung cancer mortality.  METHODS: : The method of Bashir and Esteve (2000) was applied in this study. The baseline group was the year 2000 and the comparison group the year 2010.  The mortality of these groups was assessed according: population size, structure of the population and risk. The population was age adjusted. The mortality of melanoma and lung cancer is from the National Centre of Health Statistics and the population from the Census Bureau (2000, 2010).  RESULTS:   The net change in melanoma mortality was one death; there was an increase of 6 deaths due to change in the structure and a decrease of 5 deaths due to change in the size (1) and due to risk (4). Net change in lung mortality was 22 deaths; an increase of 166 deaths due to change in the structure and a decrease of 144 deaths, 14 due to change in the size and 130 due to risk.  CONCLUSIONS: Melanoma and lung cancer mortality in Puerto Rico has been affected by the change in the demographic profile, resulting in an increase in the number of deaths for these two types of cancer.  The scope of cancer health services should be evaluated in light of this demographic change.