The study conducted in the districts of Sonepat and Gurgaon in Haryana during the year 2003-04, has analysed the cost, returns and break-even point of mushroom production on different categories of farms, and has investigated the existing marketing system along with marketing cost, margins and marketing efficiency. Simple tabular analysis, benefit-cost analysis, break-even level, price spread and marketing efficiency have been used to draw the inference. The study has revealed that (i) the fixed capital investment is more than double in large and medium farms as compared to the small farms, (ii) the use of compost has a positive relationship with the farm size, (iii) there exists a positive relationship between mushroom production and farm size, (iv) large farmers have lowest cost of mushroom production as compared to small and medium farms due to efficient utilization of fixed farm resources, (v) the producer share in consumer rupee is highest in channel-IV, followed by channels II, III and I, respectively. The channel-I is the least efficient due to the existence of more middlemen. The study has suggested that (a) mushroom cultivation being capital-intensive, the financial assistance through institutional agencies at cheaper interest rate would be the desirable entity, (b) mushroom being a highly perishable crop and prone to high temperature, marketing infrastructures such as cold storage facilities are of immense importance. Similarly, suitable arrangements are needed by the canning/processing units for the management of surplus mushroom.