Purpose: The purpose of this research is to study the relationship between perceptions of the work environment's factors and the librarian's work alienation in the Islamic Azad Universities of Tehran libraries.Methodology: The research method is Analytical survey. The statistical population consists of the 119 librarians of the Islamic Azad Universities of Tehran libraries. There are 100 questionnaires (84%) of the all 119, which were completed and returned.This study examines the rate of relationship between perceptions of the work environment's factors including Job Characteristics (Elbow Room, Task Identity, Feedback, Job Challenge), Occupational Role (Role Ambiguity, Role Conflict, Overload), and the librarian's work alienation.Findings: The research results show that the librarians under survey have a satisfaction of their workmates in common. There isn't any significant relationship between work alienation and demographic characteristics, but there is a significant relationship between work experience and the job characteristics. According to the results of this research, librarians of this research community aren't generally foreign with their labor, but the most of their grievances are about their participation in decision making, and role overload.Conclusions: Role ambiguity, role conflict and pressure have a negative correlation with the score of work alienation. Therefore, with an increase in each of them, the work alienation increases too. On the other hand, has a positive significant relationship with it, so that, with an increasing in task identity, the work alienation reduces.