An immunocompetent, healthy 12-year-old boy was presented with generalized large lymphadenopathy in the left side of the body, 1 month after a BCG vaccination with a regular dose. A Mantoux test before vaccination was negative. Histological and bacteriological findings from the largest lymph node biopsy revealed BCG'itis. The patient recovered spontaneously after 7 months. He was confirmed as being immunocompetent by normal serum immunoglobulin levels, normal B and T cell function tests, and a conversion of Mantoux test. BCG infections including lymphadenitis are rare and have been described hitherto mainly in infants, in immune deficient patients, or related to overdose. Such a complication must be taken into consideration when dealing with lymphadenopathy in healthy school-age children, who now undergo BCG vaccinations in many countries.