Background and Purpose: One of the strategies of the the health system is (participation of) private sector and relying on the market. Lack of attention to the obstacles and challenges of Outsourcing Health Services to the Private Sector may lead to failure and irreparable damage to the health system. The present study aimed at identifying the challenges of Outsourcing Health Services to the Private Sector.

Materials and Methods: This study was done in the form of qualitative research using a content analysis method conducted in a cross-sectional manner in late 2016. To this end, sampling was a purposive type and it continued until the data saturation was fulfilled.
 The participants consisted of 16 experts, managers and Quality improvement experts of hospitals  Data collection  was conducted through in-depth interviews. Content analysis approach was used to data analyzing with regard to validity, reliability, and consolidation capabilities of data.
Findings: Findings were included seven main challenges: Economic issues (4 sub-theme), Structural problems (12 sub-theme), Manpower challenges (7 sub-theme), Responsibility and accountability (4 sub-theme), planning challenges (7 sub-theme), Efficiency (5 sub-theme) and private companies (7 sub-theme). 
Conclusions: There are many challenges in Outsourcing Health Services to the Private Sector and Solv them can be a step in achieving  improve the quality of health services. Structural problems were the major issues raised by interviewees. It is suggested, administrators before Outsourcing, in order to avoid any more of these challenges