Osteoarthritis of hip joints is usually diagnosed at advanced stages of the disease when degenerative changes are evident. We propose a simple and easy tool for screening of early stages of the disease with a few or no clinical symptoms. Mobility of 200 hip joints was studied in 100 persons aged 50–70 without any earlier diagnosis of the osteoarthritis of hip joints. We found that the most frequent limited movements on hip joints were: internal rotation of 25° or less (in 44% of cases) and “four test” 25 cm or more (in 33% of cases). Basing on these findings we propose a simple Index of the Limitation of Hip Joint mobility (ILHJ) – ratio: internal rotation (in grades)/“four test” (in cm). Degenerative changes are suspected when the value of the index is less than 1. The mobility limitation of the hip joint defined by ILHJ was more frequent (44%) in men than in women (25%), in the older group of 66–70 (42%) than in the younger one of 50–55 (17%) as well as in the group with pain typical of the osteoarthritis of the hip joint (inguinal region, femur and knee) (39%) than in the group without these complaints (15%). The proposed examination of mobility of hip joints is easy and takes less than half a minute. It might be recommended to family doctors. This kind of examination performed in all elderly patients can help early detection and treatment of osteoarthritis in hip joints.