Salmonella and Plasmodium infections are major health challenges especially in regions where malaria is highly endemic. Studies were carried out to determine the incidence of co-infection of Salmonella spp and Plasmodium falciparum among subjects that present with fever at the Covenant University Health Centre and Ota General Hospital between September, 2011 and May, 2012. Salmonella infection was detected by comparing two diagnostic methods: serology and culture on the blood samples collected. Widal test was carried out by detecting the ‘O’ and ‘H’ antigens in the blood and the blood samples were cultured using Thioglycolate broth and Salmonella Shigella agar. Plasmodium infection was confirmed through microscopic examination of Giemsa stained thick and thin films of the same blood samples. Out of the 84 samples collected, 45.2% was positive for Salmonella and Plasmodium co-infection by Widal test with positive titre ≥ 1/80. Only 3.6% was confirmed for co-infection of Salmonella and Plasmodium Species when Salmonella infection was detected by culture. Among the 84 subjects 73.8% was positive for malaria alone and 67.9% for Salmonella infection alone. Laboratory confirmation of co-infection of malaria and Salmonella is essential to prevent wrong treatment and misdiagnosis.