The most problematic districts for malaria in Karnataka are Bijapur, Raichur, Kolar, Bellary, Dakshina Kannada  and Mandya.  Present study aims at analysis of eighteen years data (1991-2008) of malaria incidences in Raichur district, study of variation, fitting of polynomial function to the data, study of seasonal variation according to months and seasons and the comparison of malaria incidences over dry and irrigated areas. Maximum malaria cases were registered in Lingsugur taluk, contributing 43.77% of incidence to the total incidence of Raichur district. Majority of malaria incidences (more than 41%) are observed during the kharif season followed by rabi season (more than 33%). In both year-wise and season-wise malaria incidences, the quadratic equation (polynomial equation of degree two) gives best fit compared to linear regression model.