The antimicrobial activity about water extract of Acacia etbaica was examined by using agar well diffusion methods against five gram-positive and negative bacteria[Staphylococcus aureus (ATCC653-8), Pseudomonas aeruginosa MTCC2453, Bacillus cereus (ATCC6633), Escherichia coli MTCC739, and one local isolate (Staphylococcus epidermides)] in addition to Candida albicans (ATCC2019). this results designated that the water extract of Acacia etbaica possess antimicrobial efficacy against all tested microorganisms either (gram-positive and negative bacteria) or fungi (Candida albicans).Whereas the gram-positive bacteria (S. aureus, S. epidermides and B. cereus) with inhibition zones (21, 19.5 and 16.5) respectively was more sensitive than gram-negative bacteria (P. aeruginosa and E. coli) and C. albicans with inhibition zones 16 and 14.5 respectively. The antimicrobial effect was directly proportional with concentration of water extract where the highest inhibition zone at higher concentration 30% equal 21mm against S.aureus and the lower inhibition zone at lower concentration 5% equal 10mm against C. albicans