Empirical findings revealed that an inflated sense of responsibility has a major impact on obsessive-compulsive symptomatology (OCS). Another cognitive variable, perfectionism, is also theoretically linked to OCS. The assumption about the insufficient but necessary role of perfectionism for OCS and the view of perfectionism as a manifestation of avoidance of serious consequences led us to explore the role of an important cognitive mediator (responsibility) in this relationship. The present study aimed to explore the mediational role of responsibility for the effects of perfectionism on checking and cleaning symptom profiles of OCS in a nonclinical population in Turkey. Findings of the present study suggested that responsibility appraisals mediate effects of self-oriented and socially prescribed perfectionism on checking and the effect of socially prescribed perfectionism on cleaning. There was a partial mediation for self-oriented perfectionism on cleaning. The findings are discussed within the scope of current literature and implications for clinical applications are suggested. (c) 2005 Elsevier Inc. All rights reserved.