OBJECTIVES: Sternal dehiscence and mediastinitis are rare but serious complications following cardiac surgery. The aim of this study was to investigate the influence of the number of sternal wires used for chest closure on sternal complications. RESULTS: Sternal complications occurred in 2.4%, and hospital mortality with or without sternal complications were 2.8 and 2.7%, respectively (P = 0.60). Mean numbers of sternal wires were 7.8 in both patient groups with or without sternal complications (P = 0.79). Multivariate analysis revealed diabetes mellitus [odds ratio (OR) 1.54, 95% CI 1.01-2.34, P = 0.04], chronic obstructive pulmonary disease (OR 1.85, 95% CI 1.12-2.79, P = 0.01) and renal insufficiency (OR 1.70, 95% CI 1.11-2.59, P = 0.001) as significant risk factors for sternal complications. In high-risk patients, the use of less than eight wires was significantly associated with postoperative sternal complications.CONCLUSIONS: Particularly in high-risk patients, careful haemostasis should be done and eight or more wires should be used to avoid sternal complications.