High-sensitivity C-reactive protein (hsCRP) adds important prognostic information, not reflected by traditional risk factors, to the prediction of both the development and outcome of cardiovascular pathology. HsCRP levels also correlate inversely with cardiorespiratory fitness, an important determinant of peri-operative outcome. We hypothesised that pre-operative hsCRP should be associated with excess peri-operative morbidity and longer length of stay. Pre-operative hsCRP was measured blinded to standardised postoperative outcomes in 129 elective orthopaedic patients. HsCRP levels were divided into high (> 3 mg x l(-1)) or low (< 3 mg x l(-1)) groups (Center for Disease Control stratification). High-CRP patients had significant cardiovascular history, received cardiac medication or steroid therapy (p < 0.05). Higher pre-operative hsCRP was associated with longer length of stay: mean 7.5 days (95% CI: 6.2-8.8) vs 6.0 days (95% CI: 5.5-6.5; p = 0.03; log rank test). In 21 patients with > 8 days length of stay, high pre-operative hsCRP patients were over-represented (p = 0.04). Pre-operative hsCRP is related to length of stay and delayed postoperative complications.