The focus of this research is to characterize Rhizobium colonies isolated from root nodules of Pisum sativum plants and determine their tolerance to heavy metals Nickel and Chromium using CFU counts. The results showed that a bacterial colony isolated from root nodules of pea on YEMA medium is a milky white colony with a spherical convex surface. Biochemical analyses of the isolated colonies revealed that they were Rhizobia species, with positive results for oxidase, catalase, and bromothymol blue, but negative results for starch hydrolysis, lipase test, lysine decarboxylase, and caseinase. The presence of high levels of Nickel and Chromium resulted in a decrease in the rhizobial colony. The presence of high levels of Nickel and Chromium resulted in a decrease in the rhizobial colony. All of the colonies thrived well at pH 6 and 7, temperatures of 28o C to 30o C, and a salt concentration of 1%, according to the study.