Malaria infection is responsible for high mortality rates in sub – Saharan Africa and this is partly caused by poor infrastructure especially for diagnosis in rural areas thereby making complying with the World Health Organization policy on proper malaria tests before treatment difficult. A cross – sectional study was conducted to evaluate the validity of presumptive diagnosis in malaria infections by comparing with microscopy and CareStart™ malaria HRP2/pLDH Pf Test kit (RDT). 1000 consenting study subjects in the Outpatient Department of Braithwaite Memorial Specialist Hospital (BMSH), Rivers State, Nigeria were sampled for malaria parasites from January 2014 to June 2016. Blood samples were gotten through venous procedure and analyzed for the presence of Plasmodium using Giemsa – microscopy and RDT kits while presumptive diagnosis (presence of fever) was determined by a Physician. All results were statistically analyzed and Giemsa – microscopy was used as the “Gold standard” for malaria diagnosis. Malaria prevalence rates of 32%, 32% and 15% were recorded for presumptive diagnosis, microscopy and RDT respectively (P