We investigated the efficacy and safety of Hylan G-F 20 for the treatment of hip osteoarthritis in Japanese patients. Methods: Twenty-nine patients with hip osteoarthritis (OA) received Hylan G-F 20 injection into the hip. The visual analog scale of pain during gait (VAS-G), VAS of pain at rest, hip joint function evaluated by the Japanese Orthopaedic Association (JOA) score, health-related quality of life (HRQoL), and adverse events were evaluated before, immediately after, and at 4, 8, and 12 weeks after injection. Patients were categorized according to the severity of OA (mild and severe OA groups) and dysplasia (dysplastic and non-dysplastic groups) and these groups were compared. Results: After the injection, VAS-G improved significantly for 12 weeks. VAS-G was lower (less pain) in the mild OA group than in the severe OA group at each time point. There were no differences in VAS-G between the dysplastic and non-dysplastic groups throughout the observation period. VAS-G improved significantly in the dysplastic group after the injection. The JOA score and HRQoL demonstrated the same tendency as VAS-G. Three patients experienced worsening of local pain immediately after the injection; however, the pain on the following day was less than that before the injection in all three hips. Conclusions: Hylan G-F 20 injection into the hip joint was effective in reducing hip pain and can be used as a non-operative treatment option for hip OA in the Japanese population.