Introduction Tuberculosis (TB) remains a serious public health problem. The most serious aspect of this problem has been the appearance of TB drug-resistance (TBDR), mainly the multidrug-resistance (TBMDR). One in five TB cases in Brazil occurs in Sao Paulo State, which has about 19 000 cases per year. Since 1980, TB treatment in Brazil has been with rifampin, isoniazid and pirazinamid. Thus, TB-DR monitoring is essential to assess its trend, in order to better assist the TB Control Program (TCP).

Objective To analyse TBDR in Sao Paulo State during the 2007–2008 period.

Methodology Using ‘population proportionate cluster sampling’ we selected 30 randomised clusters to design the resistance survey. During the 2007–2008 period, all respiratory symptomatic patients of these clusters answered the questionnaire and were submitted to AFB culture and sensitivity tests (ST).

Results From the 1746 patients interviewed: 30.3% were female and 69.7% male, the mean age was 37 years, 20.0% of the patients were HIV-positive and 821 were submitted to culture and ST. The primary resistance to isoniazid and rifampin was 5.8% and 1.5%, respectively. MDRTB was 1.1% and any-resistance was 9.8%. The acquired-resistance was as follows: isoniazid, 20.4%; rifampin 12.2%; MDRTB 12.2% and any-resistance 22.4%.

Conclusions Data on TB-DR are essential to the TCP's improvement. Results of isoniazid (increase from 4.0% to 5.8% in 8 years) showed the necessity of addition of ethambutol to our treatment schedule.