Back Ground: Malaria and HIV/AIDS are the major priority medical challenges facing sub-Saharan Africa in general and Ethiopia in particular and yet little has been known so far on the clinical and public health implications of HIV and Malaria co-infection. Even if the statistical effect is modest, any interaction between these two infections would have public health significance. Objectives: A cross sectional health institution based study was conducted between mid October 2003 and mid January 2004 in three health facilities in Hadya Zone, Southern Ethiopia. The objectives of the study were to determine the prevalence of HIV malaria co-infections in the area and to describe the clinical manifestations of malaria in HIV positive and HIV negative malaria patients. Subjects and methods: A total of 337 microscopically confirmed malaria patients in the age range of 15-34 years were included in the study. A structured questionnaire was used to collect data on socio demographic and clinical variables. Physicians used a checklist of physical findings during physical check up of patients. Anonymous HIV testing was done on the blood samples of the patients using single ELISA technique by an experienced laboratory technologist. xiv Results: The HIV serostatus assessment revealed that 4.2% (14 out of 337) of the patients were seropositive for HIV. No socio demographic difference was detected between HIV positive and HIV negative malaria patients. Conclusions and Recommendations: The study concluded that the current HIV prevalence among P.faciparum malaria patients was not different from the HIV seroprevalence in the general population in the area, based on the prevalence findings from the national sentinel reports. No strong evidence suggesting an association between HIV and malaria was identified. The need for further studies with improved methodologies and designs is emphasized. Key Words: HIV, Malaria, Coinfection, Health Institution, Ethiopia