In a prospective trial of 278 patients aged over 65 years, treatment of displaced subcapital fractures was randomly allocated to closed reduction and internal fixation with a sliding compression screwplate, Moore hemiarthroplasty, or total hip treatment with a Howse semicaptive prosthesis. One year after operation there was little difference between the three groups in mortality (25 per cent) or general complications. The revision rate within the first year was highest for internal fixation (25 per cent), but many of the replacements also required a further anaesthetic for reduction of a dislocation (Moore, 11 per cent; Howse 12.5 per cent). Total hip replacement resulted in the least pain and most mobility at 1 year, while hemiarthroplasty was worst in these respects. We conclude that internal fixation and particularly primary total hip replacement should be given serious consideration in the management of the elderly patient with a displaced subcapital fracture.