The experiment was conducted at the experimental field of Olericulture Division of Horticulture Research Centre (HRC), BARI, Gazipur, Bangladesh during November 2009 to September 2010. Eleven promising tomato inbred lines were collected from Olericulture Division of Horticulture Research Centre, BARI, Gazipur, for this study. These were C11, C41, C51, C71, FP5, MP5, WP2, WP6, WP7, WP8, and WP10. Seeds of 11 tomato inbred lines were sown in seed bed on 12 October 2009. Thirty days old seedlings were transplanted in the experimental field on 10 November 2009. The experiment was laid out in randomized complete block design (RCBD) with three replications. The unit plot size was 1.0 m × 4.8 m having double row per bed and 12 plants per row and 24 plants per plot. Plants were spaced at 60 cm × 40 cm between plant to plant and row to row, respectively. The crop was fertilized with cattle dung, urea TSP, and MP at the rate of 15 tons, 300 kg, 200 kg, and 150 kg per hectare, respectively (Rashid and Singh, 2000). Half of the quantity of cattle dung and the entire amount of TSP were applied during land preparation. The remaining cattle dung and half of MP were applied before 5 days of planting. The whole of urea and half of MP were applied in 3 equal splits as top dressing at 15, 30, and 50 days after transplanting. Observations of fruit yield and yield attributes were recorded from each genotype. Collected data were subjected to MSTAT software for analysis of variance and mean separation. Based on the field evaluation of tomato hybrids in 2007 and 2008 (Islam et al., 2011), eight superior cross combinations of tomato were considered in the present study to estimate hybrid seed yield potentiality. These were C11 × C51, C41 × C71, WP2 × WP6, FP5 × MP5, WP8 × C11, WP8 × C51, WP7 × C51, and C51 × WP10. Seeds of male parents were sown in 12 October 2009 in raise seedbed, while seeds of female parents sown on 19 October 2009. Male parent was earlier than female parent to assure adequate supply of pollen for pollination of female parent. This experiment was conducted in RCB design with three replications. Unit bed size was 0.70 m × 7.5 m having single row per bed in which seedlings were transplanted in 50 cm apart. So, there were 15 plants per bed. This was done for proper emasculation and pollination of flower in each bed. In crossing block, there were 24 unit beds in which cross combinations were allotted randomly. Planting of seedling of female parents were made on 19 November 2009. In this study, a ratio of 5 females to one male plant was used. Male block was made 100 m apart from the crossing block to avoid pollen contamination. Male parent seedlings were transplanted on 12 November 2009 in a double row bed where planting geometry was maintained at 60 cm and 50 cm between row to row and plant to plant, respectively. For hybrid seed production, emasculation, artificial pollination, and seed collection were made as per AVRDC (1993). For summer season evaluation, six hybrid combinations and their respective eight parental lines were evaluated at the experimental field of Olericulture Division, HRC, BARI, Gazipur during the summer season of 2010. The two hybrid combinations, C41 × C71 and WP2 × WP6 were not included in this study since these two combinations were already released as BARI Hybrid Tomato-3 and BARI Hybrid Tomato-5. The hybrid C11 × C51 was also released as BARI Hybrid Tomato-4, it was included in this experiment as a check variety. The seeds of the hybrids and inbred lines were sown in the seed bed on 11 May 2010. Seedlings were transplanted in the main field on 10 June 2010. The experiment was laid out in RCB design with three replications. The unit plot size was 4.80 m x 2.3 m accommodating 4 rows. Each row consisted of 12 plants. Spacing was maintained at 60 cm × 40 cm between row to row and plant to plant, respectively. The crop was protected from rain providing polythene tunnel. Irrigation, pruning, mulching weeding, and other intercultural operations were done as needed. Related data for hybrids and inbred lines were recorded separately for yield and yield contributing characters and statistically analyzed using MSTAT software. However, out of eight parental lines, three of them did not flower at all (WP7, WP8, and WP10). Therefore, data generated from five parental lines are included in this experiment.