The essential oils (EOs) from peels of Citrus grandis (L.) Osbeck was investigated for their antimicrobial activities against food-related microorganisms by hydrodistillation method (HD), and microwave-assisted extraction (MAHD). The total yield of the volatile fractions obtained through HD and MAHD was 4.4 mL/g and 4.75 mL/g, respectively. The gas chromatography–mass spectrometry (GC–MS) analyses of the oils revealed the presence of different compounds in Citrus grandis EOs obtained from MAHD and HD methods, including α-pinene, sabinene, β-myrcene, α-phellandrene and d-limonene. The essential oils obtained from the two extraction methods were found to inhibit six bacteria strains including Bacillus cereus, Bacillus subtilis, Pseudomonas aeruginosa, E. coli, Clostridium perfringens and Salmonella typhi. The results of antibacterial properties of Citrus grandis (L.) Osbeck EOs against six bacterial strains showed that essential oil extracted from the HD method were more bacteriostatic than the oil extracted from MAHD method. With this result, the essential oil obtained by the HD method was more active than that of the MADH method against the bacteria.