Background
 
Obsessive-compulsive disorder (OCD) is a heterogeneous condition with distinct subtypes. This study aims to compare the severity of obsession and working memory in children with obsessive compulsive disorder and healthy children.
 
Materials and Methods: In this correlation-comparative study, 140 students (70 healthy and 70 with OCD, diagnosed according to Obsessive-Compulsive Inventory, child-version score) were selected through simple random sampling method in in Tehran, Iran, (2018-19).  The multistage cluster sampling method was applied. The subjects were selected after purposeful clinical evaluation and according to the qualifications of the study. Assessments were made using the Obsessive-Compulsive Inventory, child-version (OCI – CV), and the Working Memory Rating Scale (WMRS). Data were analyzed using SPSS software version 25.0.
 
Results: A total of 80 girls and 60 boys with a mean age of 9 ±1.36 years were studied. The correlation between working memory and obsessive-compulsive disorder of girls and boys (r= -0.482; p =0.001) at the level of p  
Conclusion
 
The findings showed that the working memory scores in both girls and boys increased by reducing the obsessive-compulsive disorder accompanied. Moreover, the working memory of the healthy group was higher than that of the patients.