Cherry type tomato for processing with determinate growth habit and increased soluble solid content is a new perspective in improving tomato product quality. A two year (2010 and 2011) open field experiment was conducted to study the effect of different water supply on the yield components (yield, fruit number per hectare, average fruit weight) of Strombolino F1, cherry type processing tomato. The seasonal effect of the two years was significant, because the precipitation totals were 410 and 159 mm in 2010 and 2011 respectively, and distribution was uneven during the vegetation period. Optimum water supply calculated from the potential evapotranspiration provided by regularly irrigation was compared to a rainfed control. The irrigated plants gave a significantly higher marketable yield, by 33 and 139% in 2010 and 2011 respectively compared to rainfed plants. The harvested fruit number per hectare showed a close positive correlation (R2=0.91) with marketable yield and a lower with average fruit weight (R2=0.69). This is in contrast to bigger fruited traditional processing varieties, which usually show closer connection between fruit weight and yield. We observed a strong positive correlation between the water supply and total marketable yield (R 2=0.98; 0.69). 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 non-marketable fruits.