A time-series analysis was conducted to study the impact of climate variability on the transmission of Japanese encephalitis in eastern China. Correlation and regression analyses were used to examine the relationship between monthly climatic variables and monthly incidence of Japanese encephalitis in Jieshou County, China over the period 1980-96. Spearman's correlation analysis showed that maximum and minimum temperatures and rainfall were all associated with the transmission of Japanese encephalitis in the county. Regression analysis suggested that monthly mean minimum temperature and monthly precipitation had a significant relationship with the transmission of Japanese encephalitis, with a 1-month lag effect. The results indicated that these climatic variables might be treated as possible predictors for regions with similar geographic, climatic, and socio-economic conditions to Jieshou County.