To determine functional outcomes after lower extremity fracture (LEF), a prospective follow-up study of patients admitted to three level I trauma centers for treatment of unilateral LEFs was conducted. In this paper we describe outcomes at 6 months after discharge from the initial hospitalization and examine the relationship between impairment and disability. A total of 444 patients met the entry criteria for the study. Of these 376 (85%) were successfully located and interviewed at 6 months; 302 (68%) returned to the trauma center at 6 months for a clinical assessment by a physical therapist. Study patients were predominantly young (mean age = 32.4), white (72%) men (70%) who were working before the injury (77%). The fractures resulted primarily from motor vehicle crashes (71%); mean hospital LOS was 12 days. Disability was measured using the Sickness Impact Profile (SIP), a well validated patient assessment of health status. The overall SIP score averaged for all patients was 10.2, denoting a moderate level of dysfunction or disability. Analysis of the 12 subscores that constitute the SIP indicate particularly high scores for ambulation (16.7 postdischarge vs. 1.2 preinjury), sleep and rest (14.0 vs. 5.1), emotional behavior (10.5 vs. 2.2), home management (15.1 vs. 2.6), recreation and pastimes (19.0 vs. 4.4), and most notably, work (33.2 vs. 8.3). Further analysis of the subgroup of patients working before the injury shows that 48% had returned to work at 6 months. Correlations between lower extremity impairment (range of motion, muscle strength, and pain) and the ambulation subscore of the SIP were high. However, correlations between impairment and more global areas of activity such as home management, work, and recreation were considerably lower. These results suggest that other factors, over and above the extent of physical impairment, significantly influence broader disability outcomes such as return to work. Further research is needed to define these factors so that effective interventions after acute care can be identified and appropriately targeted.