<p>Blackwater fever (BWF) is an unusual complication of malaria causing fever, hemolysis, anemia, and tea-colored urine; untreated, it can be fatal. Previous studies have suggested possible associations with quinine or other antimalarial treatments in some children, but the etiology is unproven. On August 12, 2022, the Uganda Ministry of Health received an alert of a “strange disease” in Kakumiro District, Western Uganda. The “strange disease” was reportedly manifesting as tea-colored urine, severe anemia, fever, and leading to death in children with malaria. We investigated to identify the strange disease and associated factors.</p>