Background: The diameter of the graft is an important determinant of successful anterior cruciate ligament (ACL) reconstruction. If the diameter of the hamstring graft can be predicted accurately, we can determine whether this graft is suitable or if we need to harvest a different one.

Methods: A cross-sectional study was conducted among 74 patients undergoing ACL reconstruction using hamstring autografts. Anthropometric variables recorded were age, gender, BMI, height, weight, and thigh length. Grafts were prepared as quadrupled or pentupled constructs and their diameters measured. The minimum acceptable graft size was 8 mm × 90 mm. Pearson correlation and bivariate analysis were used to assess associations between anthropometric variables and graft diameter.

Results: Graft diameter showed a positive correlation with patient height and significant associations with gender, BMI, height, weight, and thigh length.

Conclusion: Height was the strongest predictor of hamstring graft diameter. Patients taller than 160 cm, weighing >65 kg, with BMI >25 kg/m² and thigh length >37 cm were more likely to have graft diameters ≥8 mm. Graft diameter decreased with age, particularly after 40 years. A predictive equation based on height was developed.

Keywords: Anterior cruciate ligament, Anthropometric, Graft diameter