Objective-To investigate the characteristics and outcomes of older patients with pelvic fracture admitted to medical and geriatric wards. Methods-All patients admitted to medical and geriatric wards with a pelvic fracture over a four year period were identified using the hospital clinical coding database. Data were collected from casenotes, hospital and Family Health Services Authority databases. Where available, pelvic radiographs were graded according to the Singh index. Results-The casenotes of 148 patients (126 women) were studied; 83% (n=123) of patients suVered a pelvic fracture in low energy trauma. Mean (SD) length of hospital stay was 21.3 (17.6) days. Single breaks of the pubic rami accounted for 47.2% (n=68) of all fractures. Inpatient mortality was 7.6% and at one year was 27%. There was a marked adverse eVect on the mobility of survivors with all patients using at least a walking stick at discharge and 51.1% (n=70) needing assistance for mobility. Although 70.9% (n=83) of patients admitted from home (or warden aided accommodation) were able to return there, 84.3% (n=70) of them required extra community support. Rates of institutionalisation rose from 20.9% (n=31) at admission to 35.8% (49/137) of survivors at discharge. Altogether 93% (n=107) of 115 patients, in whom adequate quality pelvic radiographs were available, were assigned a Singh index grade of 4 or less indicating the presence of osteoporosis. Conclusions-Pelvic fractures are often the result of low energy trauma. They are associated with appreciable inpatient and considerable one year mortality. They also have marked negative eVects on mobility in the short term. They result in increased levels of dependency in terms of higher levels of community support and rates of institutionalisation. On the evidence of Singh index grading, pelvic fractures are associated with low bone density. (Postgrad Med J 2000;76:646-650)