Abstract Volatile constituents obtained by hydrodistillation of the leaves of the Malagasy endemic plant Psiadia lucida (Cass.) Drake, were investigated by GC and GC/MS. A total of 50 constituents, representing 96.9% of the oil, were identified. The main compounds were mono- and sesquiterpene hydrocarbons: terpinolene (38.0%), limonene (10.2%) and Î±-humulene (21.2%). The oil was also found to possess interesting antimicrobial activities.