Cauliflower is an important vegetable crop grown worldwide. Development and characterization of suitable cytoplasmic male sterile (CMS) lines and male fertile inbreds is instrumental in developing heterotic hybrids. A study was undertaken to estimate heterosis and combining ability in snowball cauliflower lines through line × tester analysis involving five Ogura CMS lines and seven male fertile testers. The assessment of F1s along with their parental lines for different horticultural traits revealed a wide range of heterosis. Ogu-13-01 was the best general combiner for leaf length, leaf width and plant height, Ogu-13-85 for number of leaves/plant, Ogu-101 for days to 50% curd initiation, days to 50% curd maturity and net curd weight and Ogu-119 for harvest index. The lines with better general combining ability (GCA) were involved in majority of the heterotic hybrids. The tester Kt-18 was the best general combiner for leaf width, DB-1305 for number of leaves/plant and DB-187 for leaf length, plant height, gross plant weight and days to 50% curd initiation. However, GCA alone was not sufficient to determine and identify the potential parental lines. Hybrids Ogu-101 × DB-1305 and Ogu-119 × Suprimax Late were the best specific combinations for marketable curd weight, marketable curd yield, net curd weight and net curd yield. The hybrid Ogu-119 × Suprimax Late was the best heterotic combination for marketable curd weight, marketable curd yield, net curd weight and net curd yield, followed by Ogu-101 × DB-1305, Ogu-119 × Sel-26 and Ogu-101 × DB-187. Our findings will be instrumental to identify suitable parental lines and developing heterotic F1 hybrids in cauliflower.