Aims To study the clinical and epidemiological features in eight pediatric patients with multidrug-resistant tuberculosis (MDR-TB) diagnosed from 1994 to 2005 in three hospitals in Madrid (Spain). Methods A retrospective study was performed in patients aged less than 15 years old with positive culture for multidrugresistant Mycobacterium tuberculosis and patients with negative cultures diagnosed after contact with MDR-TB. Results Pulmonary tuberculosis was diagnosed in seven patients and arthritis in one. Fifty percent of the patients were immigrants and an adult source case was found in four (50 %). M. tuberculosis was isolated in gastric juice in four patients and in synovial biopsy in one. In three patients cultures were negative but these patients had previously been in contact with MDR-TB. Two strains were resistant to isoniazid and rifampicin, four were resistant to isoniazid, rifampicin and streptomycin, one was resistant to isoniazid, rifampicin, streptomycin and pyrazinamide, and one was resistant to 11 drugs. Six patients initially received conventional treatment without improvement. Patients received therapy for 15 months (range: 12 to 18) with 3 to 5 drugs according to the sensitivity study. The following adverse effects were observed: creatine phosphokinase increase (one patient), tendinitis (one patient), alteration of visual evoked responses (one patient) and transitory psychosis (one patient). One patient required pulmonary lobectomy. All patients responded satisfactorily to medical treatment. Conclusions MDR-TB should be suspected in patients not responding to TB treatment, especially those from countries with high resistance rates. In patients with negative cultures, treatment should rely on the results of a sensitivity study in the adult source case. MDR-TB requires the use of second- line anti-TB drugs for prolonged periods with possible toxic effects.