Cauliflower (Brassica oleracea) is one of the important cruciferous vegetable crops of India. It is widely cultivated throughout the sub-tropical parts of north India. The present investigation has analyzed the costs, returns and marketing in Sonepat district of Haryana during the year 2017-18 on the basis of highest production. A total of thirty farmers were randomly selected from the various villages of Sonepat District of Haryana. Results indicated that cost of cultivation of cauliflower per hectare was Rs.211685. The average yield of cauliflower per hectare was observed 246 quintals on sample farms. The net profit per hectare was Rs.96799. The major findings of this study revealed that production of the cauliflower was profitable. Benefit cost ratios of cauliflower was 1.46. The study was found that direct marketing of cauliflower more profitable in Channel-IV Producer-consumer among all other marketing channels due to the non-existence of intermediaries between the producer and ultimate consumer.