Introduction: The supratrochlear foramen (STF) occurs to be a neglected variation in the lower end of the humerus. Generally, this foramen is absent until the age of seven years and later on, it appears in some individuals. The formation of foramen is more on the left side. Various theories have been proposed to signify the formation. Sometimes, this foramen may be misdiagnosed as an osteolytic lesion, as it appears as a translucent area above the trochlea. The prevalence of STF may vary from among the different racial communities.

Aim: To study the prevalence of STF and morphometric measurements in relation to size and distances from the epicondyles.

Material and Methods: The dry adult humeri were collected from the Department of Anatomy, JIPMER, Karaikal. All the bones were identified for the presence of STF and translucent or opaque septum. All the bones were photographed from the same distance with the micrometre scale in it. Morphometric measurements (vertical and transverse diameter) for the STF and the distance of STF from the medial as well as lateral epicondyle were calculated using ImageJ analysis software and presented in tabulated form.

Results: Total 122 bones were included in the study. Out of those 20 bones (14{L}>6{R}) showed the presence of STF. In the present study, the prevalence of STF was 16.3%. After identification, shapes of the STF were noted to categorize them accordingly. The percentage of Round STF is more as compared to oval, reniform or rectangular. The transverse and the vertical diameter on the left side were 6.7+2.3mm and 4.3+1.7 and on the right side, it was 5.3+2.7 and 4.2+3.1mm respectively. The mean distance of the right STF from the medial and lateral epicondyle was 24.1+2.mm and 23.7+2.4mm and for the left side 16.9+5.5mm and 24.3+2.2mm respectively

Conclusion: Knowledge regarding the STF is very much promising for the orthopaedic surgeons while performing intramedullary–nailing for humerus and also for the radiologist as one of the differential diagnosis for some osteolytic lesions in that area. Finally, the prevalence may differ in different communities, hence can be considered as an important indicator of racial differentiation. As the STF is more dominantly found in the lower animals, it may act an evolutionary connecting link between the humans and lower animals.