Crop coefficients (Kc) of tomato were determined at various growth stages for the total growing season. Transplanting was carried out on 16th February, 2008 and the growing period extended up till 12th of June of the same year when all harvest was concluded. Six drainage lysimeters were used to estimate the crop evapotranspiration (ETcrop) while the reference evapotranspiration (ETo) and potential evapotranspiration (ETp) were computed using agro-climatological data obtained from the meteorological station of the Department of Agricultural Engineering, Rufus Giwa Polytechnic, Owo which was boosted by an automatic weather station from the Department of Meteorology, Federal University of Technology, Akure, Ondo state, Nigeria. Daily values of crop coefficients obtained were averaged over ten days to determine decade values of crop coefficients while same were averaged over thirty days to obtain monthly values. Cumulative water use and crop evapotranspiration of tomato revealed lower values at the beginning of growing stages and increased during the period of growth to a maximum and started to decline at the middle of harvesting period to the end of the harvesting period. The average crop coefficients (Kcearly) obtained for tomato during the early growing season in the given area was 0.52 while the average crop coefficient during the midseason growth stage (KC mid) was 0.86 and the late season crop coefficient (KC end) was 0.55
