Lead as a heavy metal that found in nature and highly used in industry is one of the toxic elements for living structures. In present study investigation of effects of lead as a heavy metal on live-weight of chickens due to accumulation level in different tissues were aimed. For such a purpose one-day-old chickens were divided into two groups as experimental and control. Experimental group animals were fed by lead added (300 mg Pb/kg as lead acetate) after four weeks chickens live weights were measured and tissue samples (liver, kidney, muscle, bone) were taken for lead concentration measurements in atomic absorption spectrometer. At the end of evaluation of data it was observed that live mean weight of experimental group was significantly lower than that of control group animals (p < 0.001). On the other hand tissue lead concentrations of experimental group were found to be significantly higher than that of control group values. So it may be concluded that accumulation of lead as a heavy metal may lead to decreased rate of animal growth.