Crop diversification has been found to augment farmer’s income and employment, and to reduce poverty. An analysis of the nature and extent of crop diversification with spatio-temporal variations in the Damodar Valley Corporation command area in West Bengal is presented and the factors affecting crop diversification are identified. The spatial effect has been captured by segregating the DVC canal water course into three segments—head-reach, middle-reach and tail-end—according to the location of the area with respect to the water course. Uncertainty in respect of canal water availability in the tail-end area induces farmers to resort to higher crop diversification. The number of rural markets, distance of cultivated land from farmer’s home, and the number of adult family members engaged in agriculture significantly influence the nature of crop diversification.