The purpose of the study was to examine the relationship of perceived organization support, affective commitment and organization based self esteem of public sector nurses in Pakistan. The research was conducted in twin cities Islamabad and Rawalpindi, Pakistan. The primary data was collected with the help of survey through personally administered questionnaires from 300 respondents in a non-contrived environment during January 2013, it was a cross sectional study. Both male and female respondents were included in the study. Results of this study revealed that perceived organizational support has a significant positive association with both affective commitment and organizational based self esteem. Meanwhile, organization based self esteem perform a mediation role between perceived organizational support and affective commitment.