Catatonia is a psychomotor syndrome characterised by multiple symptoms like stereotypies – repetitive, abnormally frequent, non-goal-directed movements. A problem is the lack of unanimity regarding the number of symptoms needed for diagnosis. We describe repetitive inappropriate sexual behaviour in a patient with bipolar depression and excited catatonia with Bush-Francis Catatonia Rating Scale score of 12. Electroconvulsive therapy resulted in disappearance of catatonia and inappropriate sexual behaviour and remission of depression. A recurrent episode with similar inappropriate sexual behaviour was successfully treated with electroconvulsive therapy. We interpreted the repetitive inappropriate sexual behaviour as a catatonic stereotypy. Similar stereotypies are reported in children with autism. Tics and self-injury in patients with autism are described as a stereotypy within catatonia. The agitated depression is another possible diagnosis with the repetitive inappropriate sexual behaviour as an example of psychomotor agitation. More research is needed towards repetitive inappropriate sexual behaviour as a possible stereotypy within catatonia.