Abstract: Background and Objective: Dryobalanops lanceolata (D. lanceolata) Burck is one of the plant species from Dipterocarpaceae family which have several medicinal purposes such as mouth ulcers, abscesses, boils and cold sores. The stem barks of D. lanceolata have antibacterial and cytotoxic properties against human breast cancer. While, the tree produce a clear yellow-aromatic resin, scientific support for the essential oil from this plant and its uses is still limited. This research was aimed to obtain the essential oil from leaves of D. lanceolata and to evaluate the antibacterial activities as well as antioxidant activity by in vitro research. Materials and Methods: The essential oil from D. lanceolata leaves was characterized by gas chromatography mass spectrometry (GC-MS). This oil was obtained by steam distillation and presented eugenol (28.73%), gamma-terpinene (15.60%), 2-beta-Pinene (9.80%) and 1-Limonene (8.09%) as the major compounds. The antibacterial activity and antioxidant effect of essential oil from the leaves of D. lanceolata were determined. The antibacterial activities of D. lanceolata oil were observed in vitro on Streptococcus sobrinus (S. sobrinus) and Streptococcus mutans (S. mutans) strains. The oil was investigated against two standard references using agar well diffusion method. The antioxidant activity was assayed by DPPH (1,1-Diphenyl-2-picryhydrazyl) and using ascorbic acid as positive control. Results: The yield of Dryobalanops lanceolata oil obtained in the present study was 0.12%. The oil was active against S. sobrinus and S. mutans. The Dryobalanops lanceolata oil also has potency to inhibit the free radicals at concentration 1.5625-25 ppm, which the IC50 was 14.28 ppm. Conclusion: These results demonstrate that Dryobalanops lanceolata oil has high antimicrobial activity for bacterial that cause dental caries disease and are antioxidant.