Abstract The presence of ampicillin-, penicillin-, erythromycin- and tetracycline-resistant bacteria in the dental plaque of White, South Asian and Japanese children was investigated. There was a high prevalence of antibiotic-resistant bacteria in children from diverse ethnic groups. The median percentage of the cultivable plaque microbiota that was resistant to tetracycline was greater in South Asian (2.9%, range 0.1–17.5%) and Japanese (7.7%, range 1.3–56.2%) children than in White children (0.7%, range 0–5.6%), suggesting that ethnic differences exist in the oral load of tetracycline-resistant bacteria ( P < 0.01). Multiresistant bacteria were frequently isolated, with 42% of isolates exhibiting resistance to two or more antibiotics. This study has demonstrated that antibiotic-resistant bacteria can be readily isolated from the plaque microbiota of children from different ethnic groups.