Objective: The objective of this research was to investigate the antibacterial activity of bawang dayak from Central Kalimantan against acne-causingbacteria namely Propionibacterium acnes, Staphylococcus epidermidis, and Staphylococcus aureus.Methods: The preliminary phytochemical constituents were qualitatively analyzed. Antibacterial activity of bawang dayak ethanol extract wasperformed using disc-diffusion technique, with five variations of concentration of 1.25%, 2.5%, 5%, 10%, and 20%.Results: Bawang dayak extract contained flavonoids, alkaloids, saponins, and tannins. The inhibition zones of bawang dayak ethanol extract in fivevarious concentrations (1.25%, 2.5%, 5%, 10%, and 20%) were 7.0±1.3 mm, 8.5±0.6 mm, 9.9±0.3 mm, 11.2±0.1 mm, and 11.9±0.3 mm against P. acnes;18.8±3.3 mm, 21.9±3.3 mm, 20.8±0.6 mm, 22.0±0.2 mm, and 23.1±0.6 mm against S. epidermidis; and 14.3±3.1 mm, 13.5±0.9 mm, 14.7±1.5 mm,16.1±1.0 mm, and 20.1±0.6 mm against S. aureus, respectively.Conclusion: This present study showed that bawang dayak ethanol extract was active against all the tested acne-causing bacteria. The highestantibacterial activity was produced by 20% of bawang dayak ethanol extract against S. epidermidis.