Background: The memory deficit or forgetfulness hypothesis of obsessive-compulsive disorder (OCD) has been used to explain the maintenance of repetitive behaviors in patients, yet the majority of studies focusing on memory show inconsistent results.

  Objective: The aim of this study was to compare the working memory capacity of women with OCD and control  group.

  Methods: This case-control study was conducted on 52 subjects in Zanjan, 2010. 26 female patients and 26 healthy controls were entered the study and were matched for sex, age and educational level. They were examined using Composite International Diagnostic Interview (CIDI) and Daneman & Carpenter's working memory test. Data were analyzed using descriptive statistics and independent T-test.

  Findings: Obsessive-compulsive patients were weaker in processing capacity and total capacity of the working memory compared to the control group (P<0.001). No significant differences were found between two groups in terms of storage capacity .

  Conclusion: It seems that repetitive behaviors of Obsessive-compulsive patients are the result of their inability to remember previous behaviors and the inability to inhibit recurrent intrusive thoughts.