We present a case report of fatal falciparum malaria of a splenectomized adult Thai patient. The patient developed high peripheral parasitemia and showed signs of severe malaria with multiorgans involvement. Ultrastructure of Plasmodium falciparum-infected red blood cells in a fatal splenectomized patient and pathological features are reported for the first time with special emphasis on the role of the spleen as a modulating cytoadherence phenotype of parasitized red blood cells (PRBC). In this patient, adherence of the PRBC to the vascular endothelium of brain, kidney and lung including blood circulating cells, was noted, despite the absence of knob on the surface of the PRBC.