Abstract The essential oil from the leaves of Campomanesia guaviroba (DC.) Kiaersk., obtained by hydrodistillation, was analyzed by GC and GC/MS. Sixteen compounds could be identified, representing around 94% of the total oil. The major components were myrtenal (27.0%), myrtenol (24.7%) and trans-pinocarveol (15.7%). The essential oil was also evaluated for DPPH radical-scavenging activity by TLC autographic assay, antioxidant capacity by ORAC-FL assay and antiproliferative activity against leukemic cells lines.