This study examines whether water use is efficient in Bangladesh agriculture compared to other inputs. As agriculture is the major water using sector and water is most scarce during winter due to low annual rainfall, the government here runs many irrigation projects. Recently Bangladesh Water Development Board (BWDB) leased out these projects to various water user groups for maintenance and expenditure recovery. This study estimates a translog production function for boro rice in the 7 hydrological regions and derives marginal products of various inputs. Production functions are estimated using data collected by International Rice Research Institute (IRRI) on expenditures of agricultural inputs and returns on investment from a nationally representative sample of 1928 farm households from 64 districts of Bangladesh. Results show that irrigation water use is less efficient compared to other agricultural inputs, like land, labour, fertiliser and ploughing with power tiller.