Objective:To analyze the chemical composition of the essential oils of Curcuma aeruginosa (C.aeruginosa),Curcuma mangga(C.mangga),and Zingiber cassumunar(Z.cassumunar). and study their antimicrobial activity.Methods:Essential oils obtained by steam distillation were analyzed by gas chromatography-mass speclrometry(GC-MS).The antimicrobial activity of the essential oils was evaluated against four bacteria:Bacillus cereus(H.cereus).Staphylococcus aureus(S.aureus).Escherichia coli(E.coli).and Pseudomonas aeruginosa(P.aeruginosa);and two fungi:Candida albicans(C.albicans) and Cyptococcus neoformans(C.neoformans),using disc-diffusion and broth microdilution methods.Results:Cycloisolongifolene,8.9-dehydro-9- formyl(35.29%) and dihydrocoslunolide(22.51%) were the major compounds in C.aeruginosa oil; whereas caryophyllene oxide(18.71%) and caryophyllene(12.69%) were the major compounds in C.mangga oil:and 2,6.9,9-tetramethyl-2.6.10-cycloundecatrien-1-one(60.77%) andα-caryophyllene(23.92%) were abundant in Z.cassumunar oil.The essential oils displayed varying degrees of antimicrobial activity against all lested microorganisms.C.mangga oil had the highest and most broad-spectrum activity by inhibiting all microorganisms tested,with C.neoformans being the most sensitive microorganism by having the lowest minimum inhibitory concentration(MIC) and minimum fungicidal concentration(MFC) values of 0.1μL/mL. C.aeruginosa oil showed mild antimicrobial activity,whereas Z.cassumunar had very low or weak activity against the tested microorganisms.Conclusions:The preliminary results suggest promising antimicrobial properties of C.mangga and C.aeruginosa,which may be useful for food preservation,pharmaceutical treatment and natural therapies. Objective: To analyze the chemical composition of the essential oils of Curcuma aeruginosa (C. aeruginosa), Curcuma mangga (C. mangga), and Zingiber cassumunar (Z. cassumunar). And study their antimicrobial activity. Methods: Essential oils obtained by steam The antimicrobial activity of the essential oils was evaluated against four bacteria: Bacillus cereus (H. cereus). Staphylococcus aureus (S. aureus). Escherichia coli (E. coli ) and Pseudomonas aeruginosa (P. aeruginosa); and two fungi: Candida albicans (C. albicans) and Cyptococcus neoformans (C. neoformans) using disc-diffusion and broth microdilution methods. Results: Cycloisolongifolene, formyl (35.29%) and dihydrocoslunolide (22.51%) were the major compounds in C. aeruginosa oil; while caryophyllene oxide (18.71%) and caryophyllene -tetramethyl-2.6.10-cycloundecatrien-1-one (60.77%) and α-caryophyllene (23.92%) wer e abundant in Z.cassumunar oil.The essential oils displayed varying degrees of antimicrobial activity against all lested microorganisms. C. mangga oil had the highest and most broad-spectrum activity by inhibiting all microorganisms tested, with C. neoformans being the most sensitive microorganism by having the lowest minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values ​​of 0.1 μL / mL. C. aeruginosa oil showed mild antimicrobial activity, and Z.cassumunar had very low or weak activity against the tested microorganisms. Conclusions: The preliminary results suggest promising antimicrobial properties of C. mangga and C. aeruginosa, which may be useful for food preservation, pharmaceutical treatment and natural therapies.