The seasonal change in mortality study provides valuable insights into the extent to which environmental factors can influence population dynamics. In this work we present the results for the municipality of Chiomonte between 1800 and 1989. Demographic data have been compiled in decennial periods and have enabled the compilation of seasonal mortality indices by age group. The results obtained provided interesting elements for the assessment of man’s relationship with the environment. In Chiomonte there was a difference in the seasonality of events according to age; indeed, the summer seems to be the season during which most deaths occur in the 1-14 age group and, in particular, in the 1-4 age group. However, in winter, deaths are more frequent in the age bracket for the first year of life and in the age group over 65 years of age. In conclusion, these data have been compared with other alpine populations or other ecosystems.