Femoroacetabular impingement (FAI) has been suggested as a major cause of primary hip osteoarthritis (PHOA). We assessed the prevalence of FAI detected radiographically in a cohort that underwent total hip replacement (THR) for PHOA. Two radiologists independently assessed the retrospective preoperative radiographs (AP pelvis and lateral) of 82 subjects <55 years of age scheduled for THR. Subjects were categorized as: definite FAI, no FAI, and not possible to exclude FAI. Definite FAI was present in 36 % of subjects. FAI is common in young subjects undergoing THR for PHOA.