The objective of this current research was to investigate the mediator role of organizational justice between psychological capital and job burnout of nurses working in private sector hospitals of Islamabad and Peshawar, Pakistan. Data were gathered from two hundred and twenty three (223) female nurses of private hospitals of Islamabad and Peshawar of Pakistan. Mediating techniques recommended by Barron and Kenny ( 1986 ) were used for finding out the mediating effect of organizational justice between psychological capital and job burnout. Results revealed that organizational justice mediated the impact between psychological capita and job burnout of nurses working in Pakistan.