Malawi has experienced a forward shift in its demand for Irish potato (Solanum tuberosum) consumption. Given limited resources at farmers' disposal, meeting the growing demand will require farmers to follow the efficient path of the farm production resources. This paper, therefore, is an attempt to measure the cost efficiency of smallholder Irish potato farmers in Dedza district of Malawi using a translog cost function, inefficiency effect model and input elasticities derived from a system of cost share equations estimated by Iterated Seeming Unrelated Regression method.