In present study the capability of some microorganisms isolated from Egyptian soil to a triazine herbicide, atriazine, decomposition was assessed.  Nine atrazine-degrading bacteria were isolated from soil that received repeated exposures of the commonly used herbicides atrazine.  These isolates were belonged to genera Basilllus, Pseudomonas and Micrococcus.  One isolate showed good growth and clearing zone on mineral salts agar media amended with atrazine (at 500 ppm) as a carbon and/or nitrogen source.  This most active strain involved in atrazine degradation were selected and identified.  The strain was classified as Bacillus megaterium.  It degraded 45.8% of initial concentration of atrazine concurrent with increasing the population size from 10⁵ to 10⁸ CFU/ml culture.  Atrazine-degrading enzymes by B. megaterium appear to be induced.  No released chloride was detected from B. megaterium culture indicating that the triazine ring may be remained intact and the atrazine-metabolites not hydroxyatrazine.  Atrazine metabolites may be deethylatrazine or deisopropylatrazine.  These results indicate that B. megaterium can play an important role in the bioremediation of atrazine-contaminated sites.