This study investigated the prevalence of bacteraemia on removal of fixed appliances. Venous blood samples were taken before and after debonding and debanding for 30 patients (mean age 17 years 8 months) who had worn fixed appliances for an average of 19 months. Before removal of the fixed appliances, bacteraemia was detected in one of the 30 subjects (3%) and in four subjects (13%) following removal of their fixed appliances. The 95 per cent confidence intervals for the prevalence of post-debanding bacteraemia were 3.8 and 30.7 per cent. No significant relationship was detected between the mean plaque scores (t = -0.65, P = 0.52) or the mean gingival scores (t = 0.75, P = 0.46) and the occurrence of bacteraemia. The prevalence of bacteraemia detected following debanding in this study is considerably lower than reported for dental procedures traditionally covered by antibiotic prophylaxis guidelines.