The metastable zone width studies were carried out for various temperatures for supersaturated aqueous solutions of various inorganic materials K2SO4, Na2CrO4.4H(2)O, CuSO4.5H(2)O, NaBr.2H(2)O, NH4Cl, KNO2, NH4NO3, NaNO3 with pure and EDTA added solutions. The various factors affecting the metastable zone width are discussed and the critical nucleation parameters are calculated. The effect of temperature, chelating agent and the concentration of the solution are discussed.