Suppressive malaria prophylaxis standard-of-care is not adequate to the threat of delayed attacks after travel by the relapsing malarias. Relapsing malarias occur wherever there is falciparum malaria, with few and minor exceptions. Causal prophylaxis is effective against all malarias and prevents delayed attacks after travel. Causal prophylaxis is suitable for both short-notice and short-duration travel. Tafenoquine is a new drug that offers the advantages of causal prophylaxis with a weekly dosing regimen. Tafenoquine is 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.