India has been implementing one of the biggest Early Infant Diagnosis (EID) of HIV intervention globally. The turn-around-time (TAT) for EID test is one of the major factors for success of the program. This study was to assess the turnaround time and its determinants. It is a mixed methods study with quantitative analysis of retrospective data (2013-2016) collected from all the 7 Early Infant Diagnosis testing laboratories (called as regional reference laboratories or RRLs) in India and qualitative component that can help explain the determinants of turn-around-time. The retrospective national level data available from the RRLs was analyzed to measure the turn-around-time from the receipt of samples to the dispatch of results and to understand the determinants for the same. The 3 components transport time, testing time, and dispatch time were also calculated. Transport time was analyzed state-wise and the testing time RRL wise to understand disparities, if any. Qualitative interviews with the RRL officials were conducted to understand the underlying determinants of TAT. The Median turn-around-time ranged between 29 and 53 days over the 4 years. Transport time was significantly higher for states without RRL (42 days) than those with RRL (27 days). Testing time varied from RRL to RRL and was associated with incomplete forms, inadequate samples, kits logistics, staff turnover, staff training, and instrument related issues. The TAT is high and can be potentially reduced with interventions, such as decentralization of RRLs; courier systems for sample transport; and ensuring adequate resources at the RRL level.