Malaria should always be ruled out in patients with fever who visited the tropics in the recent past. Even a long period of time after returning or after antimalarial treatment, malaria may be present due to relaps, recrudescence or a postponed first episode. Hypnozoites of P. vivax and P. ovale are dormant stages in the liver and not detectable in the blood, but can wake moths after inoculation. In this case, we show a patient with a mixed infection with P. falciparum and P. ovale. However, due to the absence of the erythrocytic stage of P. ovale, this species was not detected and caused symptoms weeks after treatment with artemisinin based therapy.