A 35-year-old man with no psychiatric history develops compulsive complaints after the start of infliximab. Given the coincidence of initiating this drug and the occurrence of these psychological symptoms, the dose of infliximab is reduced, which resulted in a rapid decrease of the symptoms. The medicine infliximab is frequently prescribed for autoimmune disorders but in rare cases it can also cause major psychological side effects. This article aims to demonstrate the causal relationship between drug administration and the development of obsessive-compulsive symptoms. The literature could not provide an unambiguous explanation, but based on the above findings, it may be advisable to formulate clinical recommendations, in particular vigilance for the onset or worsening of anxiety or obsessive-compulsive symptoms and to seek psychiatric advice in time.