The essential oil of C. oblongifolius Roxb. stem bark was obtained by hydrodistillation. Chemical analysis by GC-MS identified 29 compounds. Terpinen-4-ol (17.8%) was a major component, together with α-guaiene (7.9%), E-caryophyllene (7.0%), myrcene (6.7%), (+)-cyclosativene (5.1%), sabinene (4.8%), aciphyllene (4.7%), pogostol (4.6%), gamma-terpinene (3.4%), α-muurolol (3.2%) and germecrene D (3.2%). The essential oil exhibited antibacterial activity against Propionibacterium acnes ATCC 6919 with an MIC of 0.125%, v/v.