Tanzania's Primary Health Services Development Program (PHSDP) started in 2007 with the aim to establish and staff an additional 5162 dispensaries, 2074 health centres and 8 district hospitals by 2017 which would implicitly increase obstetric care facility density. However, currently obstetric care facility density is not a standard Emergency Obstetric and Neonatal Care (EmONC) indicator and data on its correlation with the standard EmONC indicators is scanty. In 2015 a crosssectional survey of all hospitals, health centres and a random sample of dispensaries providing delivery services in all the 25 regions of Tanzania Mainland was conducted whereby the presence of EmONC functions in past 3 months was assessed using a standard tool. Where necessary, population data were based on the 2012 National housing and population Census and the 2010 Tanzania Demographic Health Survey (TDHS). Data were analyzed using IBM SPSS version 20 and STATA. Spatial Mapping was done using a calibrated Geographic Positioning System (GPS) Essential Software for Android and coordinates represented on digitalized map with Arc Geographic Information System (GIS). Ethical approval was granted by the Ethical Clearance Committee of Medical Research Council [MRCC], National Institute for Medical research. Of the confirmed 5207 obstetric care facilities 2405 (46.2%) were surveyed including 35.3% of all dispensaries. National Obstetric care facility density was 68/ 500,000 population, 7/500,000 of them provided all the 7 Basic Emergency Obstretic and Neonatal Care (BEmONC) functions in past 3 months. Among all the regions, 40% had attained or exceeded the international benchmark for EmONC facilities per 500,000 population. Institutional delivery rate was 79% and overall Caesarean Section rate was 5.6%. Improved obstetric care facility density was strongly correlated with improved institutional delivery; Caesarean section rate and met need for EmONC but not the quality of case management. In conclusion obstetric care facility density is well correlated with other standard EmONC indicators.