In this study, ethanol, water, methanol and acetone extracts of <I>Tulipa sintenisii </I>(Baker) were tested for <I>in vitro</I> antimicrobial activity using disc diffusion method. All of the extracts exhibited antimicrobial effect on <I>Staphylococcus auresus </I>(ATCC 6538), <I>Escherichia coli</I> (ATCC 25922) and <I>Pseudomonas syringae</I> pv. Tomato (DSM 60407 (DSMZ)). While streptomycin (10 μg) which is used for control generates a zone diameter of approximately 15 mm against test microorganisms, it is ascertained that acetone extract generates an inhibition zone diameter of 10.5 mm against <I>Staphylococcus auresus</I>, 12 mm against <I>Escherichia coli</I> and an inhibition zone diameter of 14 mm against <I>Pseudommonas syringae</I> pv. tomato. As a result of the study, it can be said that the extracts of <I>Tulipa sintenisii</I> involves antimicrobial substances against the microorganisms which are used for this study. However, much more complicated researches are needed.