Although some plants accumulate excessive metal and can grow without any toxic symptoms, the consumption of these plants by humans can be extremely inconvenient for their health. Increasing doses of Cd (0, 10, and 20 mg kg^-1 Cd) and chicken manure (0, 500, 1000, and 2000 kg da^-1) were applied to the soil to evaluate the effects of cadmium and chicken manure on growth of spinach (Spinach oleracea L.) leaves and roots and on some heavy metal concentrations. Cadmium decreased the dry weight amounts of spinach both in leaves and in roots, decreased the amounts of Cd and also other heavy metals. The highest cadmium concentrations were determined at the second dose as 75.04 mg kg^-1 in leaves, and 162.17 mg kg^-1 in roots. Improved dry weight and decreased Cr, Pb, and Fe amounts were determined with chicken manure application. However it was not found proficient to decrease Cd which was found over the limits of WHO. Because of being highly toxic to humans, health-related limits of cadmium in soils, and in plants consumed by humans have to be carefully controlled in such conditions and the threshold limits must be changed.