Though Bottle gourd [Lagenaria siceraria (Molina) Stand] has a wide range of genetic variability, very little attention has been paid to its genetic improvement and commercial cultivation. Investigations were carried out to assess the breeding value of parental lines by combining ability analysis with the Line × Tester method to understand the usefulness of heterosis breeding to develop F1 hybrids for commercial cultivation. Nine lines and four testers were crossed to produce 36 hybrid combinations. The parents and hybrids were evaluated for growth and yield characters. There were differences among hybrids and parents for all characters. Variance associated with lines indicated significant differences for all characters except days to first male flower anthesis, number of seed per fruit, and 100 seed weight. For testers, variances exhibited significant differences among genotypes except for vine length, days to first male flower anthesis, days to first female flower anthesis, sex ratio, fruit width, fruit flesh thickness, number of seed per fruit, 100 seed weight, and yield per plant. The variance due to the interaction between lines and testers was significant for all characters except node at first female flower anthesis. The specific combining ability (sca) variances were greater than general combining ability (gca) variances and the ratio of gca/sca variances did not exceed unity, indicating the predominance of nonadditive gene action for all traits. Mean performance and gca effects of parents indicated the superiority of the lines Punjab Long, Kalyanpur Long Green, and Pusa Naveen and testers NDBG-164 and Samrat for most yield attributing characters. Based on mean performance, heterosis and sca effects, hybrids from the crosses ‘Pusa Naveen × NDBG-164’, ‘Pusa Naveen × Punjab Komal’, and ‘NDBG-121 × Samrat’ could be promising for commercial exploitation of fruit yield in F1 hybrids. Number of fruit per vine and fruit flesh thickness were significantly and positively correlated with yield. From path analysis, number of fruit per vine, days to first male flower anthesis, fruit cavity size, fruit weight, days to first fruit harvest, and total soluble solids (TSS) were identified as reliable components of yield and exerted positive, direct effects on yield. When selecting the best hybrids for yield in bottle gourd, more emphasis should be given to number of fruit per vine, fruit flesh thickness, days to first male flower anthesis, fruit cavity size, fruit weight, days to first fruit harvest, and TSS. © 2016 Taylor & Francis.