This paper is an effort to explore the impact of moonlighting practices on job satisfaction of teachers of public sector universities of the province of Punjab and Federal Capital. Only main campuses of universities were included and the sample of the study consisted of all four categories of university teachers, Professors, Associate Professors, Assistant Professors and Lecturers of the target area. Twenty percent of the population was taken as sample, 533 teachers were studied to discover the impact that moonlighting has on job satisfaction. In order to identify factors responsible for moonlighting among university teachers, four factors including additional income, blocked promotion, skill diversity and job autonomy were studied. Overall the major findings of study revealed that there is significant impact of moonlighting on job satisfaction.