Suppressive malaria prophylaxis standard-of-care requires post-travel presumptive anti-relapse therapy (PART) to destroy latent hypnozoites and prevent delayed attacks in the months following travel. A diagnosis of acute relapsing malaria (P. vivax or P. ovale) in any patient requires PART to destroy latent hypnozoites and prevent subsequent attacks by them. Primaquine has been the standard-of-care for PART as 14 daily doses of 0.5 mg/kg for the past 66 years. Tafenoquine is a new drug with an indication for post-travel or post-diagnosis PART against relapsing malarias as a single adult dose of 300 mg. Tafenoquine is, like primaquine, hemolytically toxic to patients having inherited G6PD deficiency, so is prohibited in those patients along with pregnant and lactating women. Safety in children is not yet established.