Context: We hereby present a case of menstruation related psychosis. There is little known about etiology of this entity.Case Description: A 48 years old lady was referred to our clinic by her psychologist for further evaluation of menstruation related psychosis and to rule out underlying endocrine etiology. The psychotic episodes occur only around the time of menstruation. Since last two years she has had multiple admissions for brief delusional episodes. All those incidents coincided around the time of her menstrual cycle. She remains in full remission in the intermenstrual periods and does not require treatment with anti-psychotic medications. In this case we discuss the less understood phenomenon of menstruation induced psychosis. Conclusions:It is important to report cases of menstruation related psychosis to estimate the true prevalence of this rare entity. The endocrinologists should also be aware of this clinical entity, as they are likely to get referrals for such cases as it is presumed to be a hormonal problem. Abbreviations LC/MS