Electrical power systems have been developed to more advanced structures called as "smart grids". Among many other issues, demand side management (DSM) is one of the important instruments of the smart grids. DSM techniques increase the efficiency of the grid, and modify consumer's electrical demand via demand response (DR) programs using financial incentives. In this study, shiftable domestic loads scheduled by Cuckoo search algorithm (CSA) to ensure balanced load curve as much as possible while considering the consumers' preferences. The main motivation of this paper is scheduling the usage hours of the shiftable household appliances in a neighborhood by applying the recently developed metaheuristic CSA. This paper proposes an approach to increase the efficiency and lifetime of utility network by scheduling and operating shiftable domestic loads while considering consumer's demand in terms of financial benefits. Proposed CSA based scheduling mechanism is compared with that of Genetic algorithm (GA). The results reveal positive effects of the scheduling and the performance of the CSA over GA.