Background: Efforts to reduce maternal mortality to less than 70 per 100000 live births is a priority of the Government of Ghana and globally. Access to referral health facilities from rural primary healthcare (PHC) clinics for antenatal diagnostic services is critical for improving pregnancy outcomes and reducing maternal mortality. We assessed the geographical accessibility of referral health facilities from rural clinics for antenatal diagnostic services in Upper East Region, Ghana. Methods: We assembled detailed spatial data on weighted 100 rural clinics, referral health facilities, and landscape features influencing journeys in the region. These were used in a geospatial model to estimate actual distance and travel time from a PHC facility to the nearest referral facility for diagnostic services. Distribution of facilities was done using spatial autocorrelation (Global Moran's I) run in ArcMap 10.4.1. Logistics regression analysis was done utilizing STATA 14 to determine the strength of association between long distances and pregnancy outcome predictors. Findings: Of the 100 rural clinics included in the analysis, only 15% were located less than 10km (travel time: 5-30 minutes) to their nearest referral health facilities. The likelihood of a pregnant woman accessing a referral facility for diagnostic services in the region was after every 25 km (range: 0.2-62). Spatial distribution of referral facilities was found to be dispersed (p<0.05, z-score= -2.05). Likewise, the spatial distribution of the PHCs appear to be at random (p<0.05, z-score = 0.33). Logistic regression showed maternal mortality (OR=1.25, 95%CI=1.1-1.4); stillbirth (OR=1.1, 95%CI= 1.0-1.2); and miscarriage/abortion (OR=1.13, 95%CI=1.1-1.2) were significantly associated with long distance all p<0.05. Mean test results turnaround time from referred clients to the PHC clinic midwife was estimated at 15.4 (SD= 8.6, 95%CI= 13.7-17.1). No form of electronic option for communicating test results existed between the rural clinics and their referral facilities. Interpretation: There is poor geographical accessibility of referral health facilities from rural PHC clinics for antenatal diagnostic services in Upper East Region, Ghana. Targeted improvement of essential point-of-care diagnostics in rural clinics is recommended for both maternal healthcare and the general population. Funding: University of KwaZulu-Natal, College of Health Sciences Research Scholarship. Declaration of Interest: None declared. Ethical Approval: This study was approved by the Navrongo Health Research Centre Institutional Review Board/Ghana Health Service (approval number: NHRCIRB291) and the University of KwaZulu-Natal Biomedical Research Ethics Committee (approval number: BE565/17). Permission was obtained from the Upper East Regional Health Directorate prior to conducting the study. All study participants signed an informed consent prior to participating in this study.