The essential oil obtained by hydrodistillation of Carapa guianensis Aubl. (Meliaceae) leaves was analyzed by GC-FID and GC-MS. Twenty-three components were identified, which made up 93.7% of the oil. The most abundant constituents were bicyclogermacrene (28.5%), alpha-humulene (17.2%), germacrene B (11.9%), and trans-beta-caryophyllene (9.9%). Antimicrobial activity of the essential oil, as well as the crude extracts of the leaves obtained by refluxing the dried leaves with n-hexane, dichloromethane, and methanol, was determined using the disc diffusion assay. Activity against Staphylococcus aureus ATCC 29923 and Enterococcus faecalis ATCC 29212 was only found for the essential oil and the methanolic extract, at minimal inhibitory concentrations (MIC) of 400 microg/mL and 50 microg/mL.