Multidrug-resistant tuberculosis (MDR-TB) can affect persons of any age, but it remains unknown whether children are more or less likely than adults to have MDR-TB. Representative drug resistance surveillance data reported to the World Health Organization between 1994 and 2011 were analysed to test the association between MDR-TB and age group (children aged <15 years versus adults aged ≥ 15 years), using odds ratios derived by logistic regression with robust standard errors. Of 85 countries with data from nationwide surveys or surveillance systems, 35 reported at least one paediatric MDR-TB case. Aggregated data on age and drug susceptibility testing for 323 046 tuberculosis cases notified in these 35 countries were analysed. Odds ratios for MDR-TB in children compared to adults varied widely between countries. In Germany, Namibia, South Africa, the UK and the USA, MDR-TB was positively associated with age <15 years. In the remaining countries no association was established. Despite the limitations intrinsic to the use of surveillance data and to the challenges of diagnosing childhood tuberculosis, our analysis suggests that proportions of MDR-TB in children and adults are similar in many settings. Of particular concern is the association found between age <15 years and MDR-TB in southern African countries with high HIV prevalence.