We present the case of a 39 years old woman who was referred to our day hospital unit because of anxiety. The patient didn’t endorse any past psychiatric symptoms except for an acute psychotic episode in August 2010. In June 2010 she was diagnosed with hypothyroidism (likely due to Hashimoto’s thyroiditis) and was started on Methilmazole 30 mg. Shortly after that she reported persecutory ideation and hallucinations which quickly progressed, until she was hospitalized in a psychiatric facility. Upon admittance her lab work revealed severe hypothyroidism. Methilmazole was suspended, she was started on Haloperidol, and the symptoms went into remission after four days. Despite the fact that she self discontinued Haloperidol shortly after discharge, she showed no sign of psychotic symptoms. While it is widely accepted that hypothyroidism can cause depressive symptoms, to the best of our knowledge very few cases of psychotic symptoms associated with this condition have been described. Based on the patient’s clinical history, on the rapid onset and remission of symptoms, on the lab values and on the doses of medication that were prescribed, we hypothesize that our patient’s psychotic episode was caused by iatrogenic hypothyroidism.