Patients presenting to psychiatrists frequently have comorbid medical conditions for which they are receiving treatment. A range of medications used for treatment of these conditions can have adverse effects resembling psychiatric symptoms. This article presents the results of our review of the literature on psychiatric adverse effects of various non-psychotropic medications, and discusses the mechanisms of such effects, their assessment and management. Among the commonly prescribed drugs found to have psychiatric adverse effects are corticosteroids, anti-Parkinsonian drugs, anti-epileptics, antiretrovirals, antibiotics, anticancer drugs, analgesics, drugs targeting endocrine and cardiovascular disorders, immunosuppressants, skeletal muscle relaxants and bronchodilators. Some adverse effects are predictable and dose dependent, whereas others are rare and idiosyncratic, and psychiatrists need to be aware of them for accurate diagnosis and appropriate treatment.