In order to determine the incidence and acceptance of BCG scars, 287 high-school children of different ethnic origins, in a London district, were examined for their BCG scars and interviewed for self-appraisal of their scars 6-30 months after vaccination. BCG scars developed in a high proportion of children (89.5%). There was a female predominance among the 10.5% of children who did not develop scars (girls 12.8%, boys 5.9%, P < 0.05). Hypertrophic scars (defined as the largest diameter of scar > 13.24 mm, [i.e. 2 SD above mean]) were found in 3.11% and hypopigmented scars in 67.8% of the children and both tended to occur amongst hyperpigmented races. A high proportion of children found the scars unacceptable (23.4%), mostly girls (girls 35%, boys 7.8%, P < 0.0004) and they showed a preference for other sites including inner aspect of arm and buttock for vaccination.