The essential oil from fresh leaves of Plinia cerrocampanensis Barrie (Myrtaceae), obtained by hydrodistillation, was analysed by CC-FID and GC-MS. Forty components, representing more than 91% of the oil, were identified. Oxygenated sesquiterpenes represented the main fraction with a-bisabolol (42.8%) as the major constituent, making this plant a new and good source of this substance. Biological activity of the essential oil was evaluated against several bacterial and fungal strains as well as larvae from Aedes aegypti. The highest activity was found against Staphylococcus aureus, Pseudomonas aeruginosa, Microsporum gypseum, Trichophyton mentagrophytes and Trichophyton rubrum with MIC values from 32 to 125 mu g/ml. The essential oil also showed potent inhibitory and bactericidal activities against three H. pylori strains, with MIC and MBC values of 62.5 mu g/ml, and caused 100% mortality of A. aegypti larvae at a concentration of 500 mu g/ml. (C) 2009 Elsevier Ltd. All rights reserved.