Malaria is an infectious disease caused by an intracellular parasite, Plasmodium, which is transmitted to humans after the bite of an Anopheles mosquito. This disease has been prevalent for decades. It has caused great epidemics in history and has also delayed social and economic development. It is endemic in the Eastern Mediterranean and Southeastern Anatolia regions of our country. The most common plasmodium in our country is P. vivax. In P. vivax infections, patients should be treated with primaquine to eradicate hypnozoites. Here, we present a case of relapse with P. vivax, and we emphasize the importance of primaquine in the treatment.