Objectives: To examine the profitability of mulberry cocoon production and to identify the reasons for marginalization of mulberry sericulture in West Bengal, India. Methods/Statistical analysis: The primary data pertaining to socio-economic status of farmers and costs & returns of mulberry cocoon production was collected from 240 respondents (Malda, Murshidabad & Birbhum) using pre-tested structured interview schedule following multi-stage purposive random sampling. The economics of mulberry cocoon production was worked out using budgeting technique. Findings: Mulberry cultivation in West Bengal was pronounced on marginal/small farms with average mulberry holding of 0.66 acre. Cost of production per kg of mulberry cocoon on marginal farms worked out to |283 and the profitability expressed in terms of the returns per rupee of expenditure was |1.47. Inadequate land holding and labour-intensive nature of mulberry cultivation are identified as major causes for marginalization of mulberry sericulture in West Bengal. Application/Improvements: The cost estimates will serve as the basis for policy-makers to intervene for the announcement of minimum support price in the event of price crash. Labour cost formed major chunk in the total cost of production of mulberry cocoon on marginal/small farms reelecting the scope for development of suitable implements & equipments for economizing mulberry sericulture. JEL classification: Q1 Keywords: Profitability; marginal farm; small farm; Mulberry sericulture; cocoon; budgeting technique