Failure to conservative treatment in patients with less advanced radiographic signs of osteoarthritis of the hip (Danielsson grade 2-5) confronts with the decision of further treatment. Since radiographic imaging has not been proved very useful in demonstrating intraarticular structures and results of hip arthroscopies have been promising, arthroscopies have been performed in 17 hips from November 1997 to September 1998. Arthroscopic findings were exceeding preoperative imaging. In addition to cartilage degeneration, concomitant loose bodies, impinging osteophytes, degeneration of the labrum and synovial disease were found. Removal of loose bodies and osteophytes, partial resection of labral tears and partial synovectomy were performed. 1 month after arthroscopy (n = 15), mean Harris-Hip-Score was increased by 13 points und pain reduced by 39 % on average. 6 months after arthroscopy (n = 9), mean Harris-Hip-Score was increased by 14 points and pain reduced by 32 % on average. In addition to its therapeutic benefit, arthroscopy offers direct visualisation of the hip providing important information for the decision of further treatment.