n 2000, Sarker et al. presented an inventory model with deteriorating items for optimal cycle and payment times for a retailer, when a supplier allows a specified credit period to the retailer for payment without penalty. In this paper, instead of using a complicated iterative search procedure to obtain the optimal payment time and inventory cycle time under permissible delay in payment for products with deterioration, we propose a simple approach to solve this problem. Moreover, the necessary and sufficient conditions of the optimal solutions of the variable cost per unit time is established. Two numerical examples are illustrated for comparing our approach with Sarker et al.'s, and making the sensitivity analysis of parameters over the optimal solutions. The results show that our approach can produce a lower variable cost per unit time than Sarker et al.'s.