Back ground:-Acute Care module is one of Integrated Management of Adult andrnAdolescent illnesses( IMAI) modules relevant for HIV care which are interim guidelinesrnreleased for country adaptation and use to help with the emergency scale-up of antiretroviralrntherapy (ART) in resource-limited settings.rnThe module covers disease classifications and treatments for the care of acute illness such asrnpneumonia, diarrhea, fever and sexually transmitted infections in adolescents and adults.rnEthiopia is one of the first countries to adapt and apply the guide lines, however, no study tornassess the validity of the guide line in identifying the problem of patients and in leading tornappropriate management decision is performed.rnObjective: - To assess The performance of Acute Care guideline for IMAI against thernetiologic and / or clinical approach.rnMethods:- The study applied a health center based Cross-sectional study design where byrnpatients seen by nurses who use acute care guideline in one room will be seen by physiciansrnusing the etiologic andor clinical approach in another room.rnResults: - A total of 648 clients who were eligible for enrolments during the study period were included inrnthe study .63.3% of the clients were females and most 39.5 % were aged 25-34 years. In the study thernsensitivities of the guideline for URTI, pneumonia and tuberculosis were found to be 100%, 100%, and 87.5%rnrespectively. The specificity of the guideline for the mentioned disorders was 92.1%, 96.6% and 100%rnrespectively. The positive predictive value was 94.3%, 94.5%, and 100%.And the respective NPV was 100%,rn100%, and 99.4%.However, specificity for severity of pneumonia was only 40.4%.rnAccordingly in patients with diarrhea the sensitivity, specificity, PPV and NPV of the guideline for dysentery werern92.5%, 100%, 100%, and 96.6% respectively.rnThe sensitivities were 78.3% and 75.8%, specificities were 83.6% and 42.9%, and positive predictive values werern60.0% and 41.0% for the diagnosis of sever and some dehydration, respectively.rnviirnUsing the guideline sixty percent of the patients with acute pneumonia were treated with oral anti biotic and IMrnantibiotics were given to 29.3% of them. However the physicians decided to treat 3 patients identified as severrnpneumonia cases using the guideline with IM antibiotics and only 26.7 of acute pneumonia cases were treatedrnwith IM antibiotics.rnMost patients diagnosed as dysentery were treated with oral antibiotics both by the physicians and the healthrnworkers using the guideline, though 5.4% of them were sent to home only with ORS and advise on additional fluidrnintake by the group using the guideline.rnConclusion & Recommendation:-The findings of the study suggested that syndromicrnmanagement of the mentioned diseases at the health center level is possible. However, the performance of thernguideline was very poor regarding level of severity in pneumonia, anemia and dehydration. Therefore the testedrnguideline needs further modifications with emphasis on its ability in delineating the level of severity.