Acknowledging government's failure to implement health promotion approach in Pakistani schools, and recognizing the need for research in this area, this study was initiated with the purpose of providing exploratory insights into the barriers that are hindering implementation of health promoting schools. Both qualitative and quantitative techniques were used. Qualitative study involved interviews and content analysis. Quantitative analysis used multi-criteria decision-making (MCDM) method, called as Fuzzy AHP. Ten important barriers were identified in qualitative analysis. The quantitative analysis identified five most important barriers; little infrastructure, poor behavior of community, lack of govt. support, lack of health promotion skills, and lack of legislation and policy. Although the results of this research are promising for targeting some specific barriers to HPS, how these barriers can be overcome is less clear. Future researchers can approach the experts for identifying possible solutions to these problems. This research informs that any effort towards implementation of health promoting schools in Pakistan will require contemplating barriers identified in this research. This research contributes to school health promotion literature by identifying possible variables which can impede the implementation of HPS approach. Moreover, the application of Fuzzy AHP technique provides sophistication in determining the relative importance of barriers to health promoting schools.