An obsession is defined as an excessive thought or impulse that constantly comes to mind involuntarily, is difficult to get rid of, causing distress and anxiety, despite efforts to forget and prevent it. Compulsions, on the other hand, are stereotyped repetitive behaviors or mental actions that are performed despite the opposing will of the individual at the conscious level in order to get rid of the ideas revealed by the obsessions, although they are known to be unnecessary and meaningless. Obsessive-compulsive disorders (OCD) are considered as distinct and specific disease from other mental disorders. There are various sub-symptom groups of obsessive compulsive disorders (OCD), which significantly affect an individual's level of life and quality. In addition to obsessions in the form of pollution and contamination, symmetry and order, doubt and uncertainty, religious obsessions are also one of the frequently seen mental disorders. It can be said that the closest equivalent of obsessive compulsive disorders (OCD) in Islamic literature is waswasah (scrupulosity). As a matter of fact, waswasah is described as a phenomenon that should be protected from in the Qur’an and hadiths. In this context, some religious words and behaviors, which can be considered as obsessive-compulsive disorder (OCD) and defined as waswasah in the classical literature, are discussed in terms of religious responsibilities in the fiqh literature. In this study, it is aimed to examine these disorders in terms of fiqh through some examples of religious obsessive compulsive disorders. Thus, on the one hand, answers to the fiqh questions of individuals who have difficulties in their religious life due to the aforementioned mental disorders will be sought, and on the other hand, the effects of such mental disorders on religious obligations will be investigated.