Background & objectives: An investigation was carried out in Thailand to study the correlationbetween rainfall and prevalence of dengue infection during 2002–03, which can be used for preventionand control of the disease.Methods: Rainfall data (2002–03) collected from Ministry of Public Health were utilised fortransformation of the infection and the rainfall data were derived from Royal Irrigation Department,Thailand. The correlation between the rainfall and the prevalence of dengue was assessed byregression analysis.Results: The least square equation plot prevalence (y) versus rainfall (x) is y = 3.0x + 4.6 (r = 0.78,p < 0.05) (r = 0.68, p < 0.05).Interpretation & conclusion: The study indicated that the prevalence of dengue infection in Thailandmay depend on rainfall. Therefore, the surveillance and control of mosquito should be intensifiedduring the period with high rainfall is recommended. However, the other confounding factors likeambient temperature and humidity which also determine the transmission of dengue should belooked into, before concluding that the increased prevalence is a result of rainfall alone. Further,similar studies to assess the correlation between the rainfall and prevalence of infection in the othercountries are required to confirm these observations
