Abstract This report describes a case of secondary obsessive-compulsive disorder related to diaschisis after pontine infarction. A 71-year-old male developed obsessive images, after a pontine infarction. A brain magnetic resonance imaging scan showed a low intensity area in the right pons on T1-weighted image, while brain single photon emission computed tomography showed low cerebral blood flow in the temporal lobe as well as the pons. In this case, infarction in the pons appeared to cause dysfunction in the temporal lobe via the neural projection network, an example of so-called ‘diaschisis’. This case suggests that brainstem infarction and decreased temporal lobe perfusion can lead to secondary obsessive-compulsive disorder.