The mechanism of action of selective serotonin reuptake inhibitors (SSRI) is still not properly established. It is essential to consider their positive and negative side effects before prescribing. In this article, we describe several of these side effects in the context of common pathologies and clinical situations. We discuss their cardioprotective effect and their role in the functional recovery of patients following stroke. We recall the increase in the risk of bleeding when prescribing SSRI concomitantly with antiaggregating and anticoagulant treatments. Prescribing SSRI also increases the risk of fracture and the frequency of hyponatremia. In the context of COPD, the effects of SSRI are more difficult to establish.