During the month of August, 2007, a 30-year-old Spanish tourist traveled through the Brazilian Amazon region of Manaus, where, due to gastric disturbances, he took an incomplete chemoprophylaxis consisting of proguanil and chloroquine. Upon his return to Spain 30 days later, he presented to a health center with an eight-day history of fever, chills and dry cough. He was diagnosed with lower respiratory tract infection and treated with amoxicillin-clavulanic acid 875/125 mg every 8 hours for 24 hours (3 doses) without resolution. On presenting a week later to Hospital Clinic in Barcelona, he had high fever (39°C) and jaundice; the tip of the spleen was palpable and chest auscultation was unremarkable. A thin blood smear of peripheral blood stained with Giemsa revealed P. vivax infection with a parasitaemia of 1.8%. The patient presented acute respiratory conditions requiring admission to the intensive care unit (ICU).