The anterior cruciate ligament (ACL) of the knee is one of the most frequently injured ligaments among young, athletic individuals. Previous research suggests that various anatomical factors contribute to both ACL tear incidence and predict changes in joint space width (JSW). However, investigation of simultaneous JSW with other anatomical measures tends to increase the imaging load required. Furthermore, each modality can include limitations such as small scanning region, high radiation dose, and weight-bearing tradeoffs. A recent addition to this field is bi-planar radiology (EOS Imaging) which offers simultaneous weight-bearing lateral and anterior views with novel low radiation exposure. The purpose of this study is to identify whether JSW measured by bi-planar imaging results in accurate and precise measurements of JSW. Our validation cohort of uninjured individuals (N=30, 26.7 ± 5.1 years) underwent scanning to determine the short-term precision of the technique, involving two repeated scans per bi-planar radiograph and conventional tunnel view knee radiograph (4 scans total). The minimum apparent JSW was collected for each leg side and compartment. When the root mean square coefficient of variation (RMSCV) and least significant change (LSC) were measured, the bi-planar scans (RMSCV= 6.46%, LSC=1.07 mm) had improved or similar within scanner precision on average compared to conventional X-rays (RMSCV=7.66%, LSC=1.15 mm). When assessing the JSW accuracy by participants, there was a bias for higher JSW by bi-planar imaging than X-ray (p<0.01). Furthermore, the bi-planar standing position, performed with the left leg semi-weightbearing, resulted in a significantly higher JSW measurement (p<0.01) in the left leg. This study emphasizes that while JSW measurements remain highly susceptible to variability, bi-planar scanners are highly reproducible. While radiography remains accessible clinically, accurate and precise JSW by bi-planar scanners is feasible provided knee position and alignment controlled.