Steroid treatment has been widely used for immunologic and inflammatory disorders. Psychiatric symptoms are not uncommon complications of the corticosteroid treatment. Correlations between the hypothalamic-pituitary-adrenal (HPA) axis and various psychoses have been already established in the specialty literature (modified HPA activity by drugs or not, glucocorticoid receptors downregulation, reduced hippocampal volume). The prevalence of corticosteroid-induced psychotic disorders varies around 5–6%. Most corticosteroid-induced symptoms start during the first few weeks after treatment initiation, but their onset can also be in the first 3–4 days. We would like to report the case of a 30-year-old woman who was taken to the psychiatry emergency room for psychomotor agitation, auditory and visual hallucinations, and bizarre delusions, disorganized thinking and modified behavior. The patient had no personal or family history of psychiatric illness. One month earlier, she was admitted in a neurosurgery ward and underwent lumbar surgery for L4–L5 disc protrusion; at discharge, eight days later, she began treatment with methylprednisolone 80 mg/day for three days. One week later, psychotic symptoms emerged that resulted in her hospitalization in our ward for apparent steroid-induced psychosis. Treatment with risperidone (up to 6 mg/day) and diazepam (10 mg/day, rapidly discontinued) was initiated. The endocrinology examination revealed modified plasmatic cortisol. The psychosis resolved several weeks later and the patient was discharged. Psychiatric complications induced by steroids underline the role of physicians that have to educate the patients and their families about these side effects and their early recognition.