Background. Medications are not exempt from adverse drug reactions (ADR) and how the physician perceives the risk of prescription drugs could influence their availability to report ADR and their prescription behavior. Methods. We assess the perception of risk and the occurrence of ADR associated with COX2-Inbitors, paracetamol, NSAIDs, and morphine in medical students and residents. Results. The analgesic with the highest risk perception was morphine, while the drug with the least risk perceived was paracetamol. Addiction was perceived as the most probable adverse effects developed by morphine. In the case of NSAIDs, the main adverse effect perceived was GI bleeding. Discussion. Our findings show that medical students give higher risk scores than residents toward risk due to analgesics. It is probable that both groups of students have morphinophobia, although more studies are necessary to confirm this. Continuing training and informing physicians about ADRs is necessary since the lack of training is known to induce inadequate use of drugs.