Although most of the adverse events derived from dry needling are minor, avoiding potential hazards for patients including accidental invasion of vessels, ganglia, and nerves is essential to ensure patients’ safety. We aimed to investigate the contribution of predictors explaining the variance of sartorius muscle depth limit at proximal third and middle thigh as these locations lead to an augmented risk of neurovascular bundle invasion during dry needling application. A diagnostic study was conducted on 84 subjects to calculate the accuracy of a prediction model for sartorius depth, as assessed with ultrasound imaging, based on sex, age, height, weight, body mass index (BMI), thigh perimeter, and length. After calculating a correlation matrix, a multiple linear regression analysis was performed to detect those variables contributing to the sartorius deep limit in both locations. Although males showed greater thigh perimeter than women (pp = 0.003) and the mid-third (p = 0.004) points. No side-to-side anthropometric differences were found (p > 0.05). In addition, we found sartorius muscle depth to be associated with the proximal and mid-third girth, gender, height, and BMI (all, pView Full-Text ►▼ Show Figures This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.