The purpose of this research was to analyze and evaluate the influence of mindfulness group training on the rate of obsessive- compulsive disorder symptoms. The experimental method was used in this research; that is, pretest- post test with control group. The participant's were120 fondles who were clients of private & state clinical centers in Isfahan (fall 2010). In an interview, based on the revised text of the fourth diagnostic & statistical guide in mental disorders, the clients were diagnosed as suffering from obsessive-compulsive disorder. From among 120 clients, 24 people were randomly selected and were assigned to 2 groups of experimental and control group. The experiential group received 8 sessions of treatment, that were held twice a week & each session was about 2 hours. The participants of the control group have filled the questionnaires without any instruction or treatment.3 The results of analysis of covariance showed that the training effects of mindfulness on general symptoms of obsession in post- test & a 2 months follow-up were significant (P<0.0001). In addition, the results showed the effect of training on washing/ cleaning (P<0.05), verification (P<0.001), clueless (slowness) (P<0.0001) & obsessive hesitation (P<0.0001) symptoms in post- test & follow-up after 2 months was significant.Therefore considering the effects of this training and its advantages in treatment of obsessive-compulsive disorder is suggested.