Rainfall pattern of Sirsi region of Kamataka state for 48 years period (1955-2002) was analysed for annual, seasonal and monthly period and its effect on the existing cropping system was studied.  The rainfall analysis showed that there are 1 1 deficit years (22.9 %), 28 normal years (58.3 %), 8 excess years (16.7 %) and 1 wet year (2.13 %) in 48 years with a coefficient of variation of 24.4 per cent.  Month wise analysis of rainfall revealed that the maximum mean rainfall was received during July (929.5 mm) followed by August (541.0 mm) and June (530.5 mm) months.  The seasonal rainfall analysis indicated that the monsoon season accounted for 87.6 % (2170.4 mm) of total rainfall with a least coefficient of variation of 27.3 per cent.  The average total rainfall during June to November period was 2353 mm which coincides with growing period of rice (major crop of the region) accounts for more than 90 % of the average total rainfall and the whole season was found to be normal during all the years of study period.  The probability of getting rainfall of 100 % and above, 75 % and above and 50 % and above of the average rainfall during the rice growing season was 47.9, 83.3 and 100 per cent, respectively.  This indicates the surety of getting water needed for successful cultivation of in Sirsi area.  For taking up of a rabi crop, the rainfall of post-monsoon (October to December) plays a great role.  During different years, more than 56 per cent of the years have normal post-monsoon seasons.  The probability of getting rainfall at 100 % and above, 75 % and above and 50% and above during post-monsoon season was 43.8, 56.2 and 81.3 per cent, respectively.  Hence, a short duration pulse crop can be taken on the residual moisture in rice fallows in Sirsi area.