This article discusses the place of the psychiatric field in the ongoing phenomenon of religious radicalization. First, the article provides an overview of the existing literature on lone‐actor terrorists and the link with mental illness. Current research is focusing increasingly on lone‐actor terrorists. This is the most recent and rising development on the global terrorism scene. The literature is currently developing a more precise and informed definition of lone‐actor terrorism. The article then describes and discusses the case study of a mentally ill patient arrested following his assault on a military serviceman on the grounds of religious radicalization. The patient, diagnosed with schizophrenia, is taken as an example of the specific case of religious radicalization in patients with schizophrenia. Finally, the article discusses the curative and preventive roles that can be played by psychiatrists and other professionals who are in contact with these types of patients.