This study includes ecological and environmental conditions with survey data collected in 1978 in Yaounde, Cameroon on infant and child mortality rates to study the effects of climate on death rates and project the seasonality of deaths. The survey consisted of several different stages: 1) a survey conducted on pregnant women in maternity hospitals from January 1 to December 31 1978; 2) follow-up a month post-partum; 3) a 2nd follow-up 4 months post-partum; 4) 5 consecutive stages at 4-month intervals so that each infant was followed for the first 2 years of his life. In 1978 out of 9782 live births, 5,856 infants were alive by the 7th follow-up; 580 had died by the 2nd year of the survey and 3,346 had dropped out of the survey. Results of the survey concluded that for infants 1 year, mortality was mainly caused by infectious and parasitic diseases. Measles was most prevalent during the hottest season (March); while diarrhea, the 2nd most prevalent cause of death, occurred most during the rainy season.