Ethanol and aqueous extracts of Amaranthus spinosus (roots) were investigated for their antibacterial activity against ten bacterial strains including Gram-positive and Gram-negative bacteria using the agar-well diffusion method. The 2 extracts tested, the ethanol extract presented the best results while the aqueous extract showed moderate inhibition of the microbial growth. Each extract is unique against different microorganisms. It is concluded that the plants studied may be a source of antibacterial agents.