A strain ofKlebsiella aerogenesisolated from Rustamiyah Station for treatment of wastewater was examined for its ability to grow in a media supplimented with maximum tolerance concentrations of Pb++, Zn++, Ni++and Cd++, separately, at different temperature and initial pH. The results indicated that at 28°C and during the first 24hr, Pb++and Ni++had no effect on the growth of the bacteria, while the presence of Zn++and Cd++decreased the cell count. The growth reached a maximum level after the second day and started to decrease gradually.