This paper develops a production inventory model for deteriorating items under fuzzy environment. Since holding cost, set-up cost, deterioration cost, deterioration rate, production rate, demand etc. are uncertain in nature; these are carried by pentagonal fuzzy numbers. Graded Mean Integration Representation (GMIR) method is used to defuzzify the total cost function. Numerical example is given to explore the theoretical results and made the comprehensive. Sensitivity analysis with different parameters on the optimal solution is carried to illustrate the effectiveness and behavior of the model.