The classical inventory models usually consider deterioration rate and demand rate as constant quantities, but, in the practical situations, the deterioration rate and the demand rate are uncertain in nature. In this paper, a new two-warehouse inventory model with fuzzy deterioration rate and fuzzy demand rate under conditionally permissible delay in payment is developed. The deterioration rate and demand rate are considered as right-shaped fuzzy numbers. The objective was to obtain the optimum value of the fuzzy total cost. The numerical examples are also considered to compare the crisp model and its corresponding fuzzy model. Finally, a sensitivity analysis is carried out to get the sensitiveness of the tolerance of different input parameters.