Six parental lines of indeterminate tomato were used in half diallel model to study performance, degree of heterosis and combining ability.This study was conducted at the Experimental Farm, Faculty of Environmental Agriculture Sciences, Arish University during two successive seasons of 2018/2019 and 2019/2020. Results revealed that the parental lines IRS-43-2, VR-6 and VL-5-4 exhibited the best values for most studied characters,however the cross combinations IRS-43-2 x VR-6, IR-44-2 x VR-6 and VR-6 x VL-5-4 were the best among the crosses.Hybrid vigour was observed in many traits, the significant positive heterosis over the check hybrid was detected in all characters and the highest values were reflected by the crosses VR-6 x VL-5-4 for growth traits and IRS-43-2 x VR-6 for early yield, total yield and Vit. C content. Variances of combining ability and genetic components revealed that additive gene action played the main role in the inheritance of fruit set percentage, total yield plant-1, average fruit weight, fruit shape and Vit. C. Based on GCA effects, the good combiner was Vl-5-4, for growth traits; IRS-43-2 and VR-6 for early yield, total yield, number of locules, and Vit. C. The highly significant positive values of SCA effects observed in crosses VR-6 x VL-5-4 for growth traits and Vit. C; IRS-43-2 x VL-5-4 for early yield; and IR-44-1 x VL-7-4 for total yield and average fruit weight. Three promising crosses (IRS-43-2 x VR-6; IR-44-2 x VR-6; VR-6 x VL-5-4) could be used commercially as local hybrids after testing in multi locations and seasons.