The aim of the study was to determine if doxycycline causes tooth staining in young children. A dentist examined 31 randomized children who had been treated with doxycycline and 30 children who had not received doxycycline. Mean age of the children was 10.4 ± 2.1 years. Mean age at receipt of the first doxycycline treatment was 4.1 ± 1.6 years, and mean number of doxycycline courses was 2.0 ± 1.3. No tooth staining was detected by the dentist in any of the children in either group. These findings indicate that treatment with doxycycline in children aged 2 to 8 years is not associated with tooth staining.