Prompt Gamma Neutron Activation Analysis (PGNAA) is a fast, online and the non-destructive elemental analysis method which is widely used in industries such as cement and coal. In the present study, optimization of the moderator and gamma radiation shield of a Cf-252 neutron source in a PGNAA setup, utilizing Monte Carlo simulation is succeed. The objective is to enhance the thermal neutron spectrum and minimize potential gamma rays. The results show that high density polyethylene (HDPE) with a thickness of 5 cm as the moderator and lead with a thickness of 4 cm as the gamma radiation shield are the best options for the intended purpose. As a result of this optimization, increased efficiency of the PGNAA setup through (n(th,gamma)) reaction and elevated prompt gamma flux which provides higher accuracy for the detector system. Copyright (C) 2016, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.