Cherry type tomato for processing with determinate growth habit and increased soluble solid content is a new perspective in improving tomato product quality. A three year (2010-2012) open field experiment was conducted to study the effect of different water supply on the yield components (yield, fruit number per ha, average fruit weight and °Brix) of 'Strombolino' F1, cherry type processing tomato. The seasonal effect of the three years was significant, because the precipitation totals were different in all three years. Calculated optimum water supply (WSO) was compared to a rainfed control (WSC). The irrigated plants gave a significantly higher marketable yield, by 116, 205 and 522% respectively compared to rainfed plants. We observed a strong positive correlation between the water supply and total marketable yield (R2 = 0.45). Increasing water supply increases fruit yield but reduces the ratio of healthy fruits. Indeterminate cherry type processing tomato are more responsive to seasonal variation of weather, especially rain during the ripening period, because of their higher sensitivity to fruit cracking, which results in nonmarketable fruits.