Objective: To describe the correlation between the length and diameter of semitendinosus tendon (ST), and weight, height and age in Hispanic population. Methods: Prospective study of a consecutive series of 61 patients that underwent anterior cruciate ligament (ACL) reconstruction with hamstrings; 40 (67.2%) males and 21 (32.8%) females. The average age was 28.3 ± 10.2 years (range 17-55). In the operating room, length and diameter of ST folded in four bundles (ST4) were measured. Correlations were calculated using patient weight, height and age, including males and females and separating them by gender. Results: Mean ST4 diameter: 9.0 ± 1,3. mm. Males ST4 diameter: 9.3 ± 0.8. mm; females ST4 diameter 8.3 ± 0.6. mm (p < 0.05). Average ST length: 28.1 ± 3.4. cm. Males mean length 28.5 ± 2.3. cm; females mean length 26.0 ± 2.5. cm (p < 0.05). Weight was correlated directly with ST length (c = 0.47; p < 0.001) and ST4 diameter (c = 0.51; p < 0.001). Patient height was directly correlated with ST length (c = 0.57; p < 0.001) and ST4 diameter (c = 0.34; p = 0.008). There was no correlation between patient age and tendon measurements. Conclusion: A positive correlation was found between ST length and patient weight and height for the general population. A direct correlation was also observed between ST4 diameter and patient weight and height for the general population. © 2010 SECOT.