Lead (Pb)⁺⁺ is a persistent and  common environmental contaminant that can be detected in all phases of biological system. The present study was designed to investigate the lead acetate [Pb(C₂H₃O₂)₂]  induced histological changes in heart. Normal healthy looking mice showing no sign of morbidity were divided into three groups. Group I was designated as control whereas group II and group III received lead acetate having doses 10 mg/kg body weight of lead acetate, daily and 150 mg/kg body weight of lead acetate, weekly respectively. Study was performed at 40 and 80 days stages. Lead acetate given in low dose (10 mg/kg body weight) and high dose (150 mg/kg body weight) caused dose dependant changes in the anatomical cellular organization in relation to normal tissue. Treated mice at 40 and 80 day stage showed poloymorphonuclear leucocyte (PMNL) infilteration which could be seen between myofibres and around necrotic sites to scavenge the damaged fibres in cardiac muscles. Clumping of nuclei to one side of vessel is also seen.