Tuberculosis (TB) has been a major health problem in developing countries including India. Due to increase in multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis, there is an urgent need of finding newer anti-mycobacterial agents to combat this problem. Natural sources provide numerous examples of interesting secondary metabolites with anti mycobacterial activity, indicating that natural products could be a rewarding field for the discovery of new anti-TB leads. In the present study, aqueous extracts and ethanolic extracts of selected medicinal plants used as spices (Allium sativum, Allium cepa, Syzygium aromaticum, Cinnamomum verum) were observed to have anti-TB activity against M. tuberculosis H37Ra and (Zingiber officinale, Camellia sinensis, Curcuma longa, Elettaria cardamomum) had poor/no activity against M. tuberculosis H37Ra. The growth and minimum inhibitory concentration (MIC) (μg/ml) in which the aqueous and ethanolic extracts of medicinal plants inhibits M. tuberculosis H37Ra by microplate Alamar blue assay (MABA) method after 7 days of incubation at 37°C were reco rded, and according to our results, A. sativum, A. cepa, S. aromaticum, C. verum could be used as adjuvant therapy for TB. © 2011 Academic Journals.