OBJECTIVE: The goal after hip arthroplasty and hip trauma surgery is to restore normal anatomy and hip biomechanics. Vertical offset directly affects limb length in arthroplasty. Limb length inequality that occurs after arthroplasty might lead to pain, claudication, nerve palsy and serious dysfunction. The aim of this study is to define a new alternative measurement method for vertical offset evaluation. MATERIAL AND METHODS: In our study, we investigated whether the distance between trochanter major and acetabular roof (ASTM) is a safe method for determination of limb length. We evaluated 404 hips of 202 patients, aged between 18 and 65 years without any hip pathology. ASTM was measured for each hip on pelvic radiographs. We based on two lines for measurements: The first line is the line connecting the highest convex subchondral points on the superior of both acetabulum. The line connecting the highest bone protrusions of the both trochanter majors is the 2nd line. The distance between these two lines and measured on the trochanter major was defined as ASTM. Measurements were made by two different authors in two different time periods. The intra-observer and inter-observer reproducibility was evaluated by the calculation of the intra-class correlation coefficient (ICC) for each measurement. RESULTS: The average ASTM value in men were 27.6 ± 0.72 mm for right side and 28.4 ± 0.7 mm for left side; these values were 22.5 ± 0.56 mm and 22.7 ± 0.57 mm for women. Consecutive measurements of each observer were found to be consistent (P<0.001). Interobserver reproducibilty was high when both observers’ measurements for each hip considered (P<0.001). ASTM was found to be significantly inversely related to age (P<0.001). There was no statistically significant relationship between weight and height, and ASTM. CONCLUSIONS: According to our the results, ASTM measurement is a reproducible method and intra- and inter-observer measurement reliability is also high. Since the method does not use the trochanter minor as a reference point, it is exempt from problems arising from trochanter minor offset measurement. However, it cannot be used in acetabular dysplasia-like pathologies. We think that ASTM measurement can be used as an alternative method in the evaluation of hip vertical offset.