Basil (Ocimum basilicum L.) is one of the aromatic plants that show great morphology diversity such as inflorescence, leaf and aroma profiles. In world scale, basils have been widely used as a culinary herb. The essential oils of basils were used as food flavourant, medicines and in perfumery industry. In this study, different accessions of Ocimum basilicum L. from different regions were introduced and cultivated in Malaysia. The morphological variability, chemical compositions and antibacerial activity of the basil essential oils were studied. Morphology of the basils is distinctly differed. The yield of basil essential oils varied. The chemical variability among abroad basil essential oil was extremely broad. Chemical compositions of fixed oil revealed that basil seeds oil contained high linolenic acid. The chemical and biological studies of the basil plant are important in helping to protect the plant biodiversity by introducing as a new agricultural crop in Malaysia which can be used as one of the natural resources in producing medicine and hygienic product.