Sparteine is an alkaloid with bacteriostatic activity on the genus Mycobacterium. The objective of this research was to evaluate the antimicrobial activity of sparteine on the growth of 4 ATCC strains of My-cobacterium tuberculosis (susceptible, resistant to isoniazid, resistant to rifampicin and multidrug-resis-tant) in vitro. Validation of bactericidal activity of sparteine sulfate was carried out through an adaptation of the Microscopic-Observation Drug-Susceptibility (MODS) method according to the guidelines of the Peruvian National Health Institute. The results demonstrate that at concentrations of 25; 50 and 100 mM of sparteine sulfate, there is no development of colony-forming units in any of the 4 strains evaluated. The results demonstrate the potential in vitro antimicrobial effect of sparteine on multidrug-resistant tuberculosis.