Rural underfives (5335) were followed for a period of one year from January to December 1987 for acute respiratory infections (ARI). Those affected with pneumonias were studied in detail to know the epidemiology. The children reported an attack rate of 0.29/child/year. Severe cases constitute 0.5%. Infants had higher attack rate (0.59/child/year), 47.7% of episodes occurred in infants and 87.7% occurred in children below 3 years. Males had a higher attack rate (0.32 vs 0.27). Mean duration of attack was 5.45 +/- 1.95 days. The attack rate was higher in winter. The case fatality rate was 1.26%. It was highest in neonates (10.7%) Females had higher case fatality rate than males (1.5% Vs 1.1%). Mortality was very high in severe cases. Case fatalities were high in seasons when the climatic change occurred, the highest being in autumn.