Background: In 2015 Tanzania’s health ministry through the National AIDs control program provided new guidelines concerning management of HIV/AIDs. Among them are the laboratory investigations supposed to be performed prior to ART initiation. These investigations are important as they have an impact in morbidity and mortality of the patients. This study’s aim was to evaluate these investigations. Objective: The objective of this study was to evaluate baseline laboratory investigations prior to ART initiation for newly diagnosed HIV patients at Primary Health Care facilities in Moshi municipality in the year 2015 Methodology: This study was a retrospective cross-sectional study that involved reviewing of patients’ records for patients aged 14 or above attending at CTC clinics in Moshi municipality. Patient’s records were obtained from medical records after being identified from the ART registrees. A well structured data collection form was used to record the data. Results: At total of 201patients’ files were involved in the study. CD4 tests. TB screening and prior to ART initiation were done in 187(93%) patients. LFT, RFT and HB tests were found to be done at a low percentage. Discussion: CD4 and TB screening are the investigations mostly carried out among others. We recommend to the government to make sure that the machines and other equipment required for the baseline investigations are available and in working conditions at the health facilities