THIS study aimed to investigate the pathogenesis of locally isolated Salmonella Gallinarum biovar Gallinarum in experimentally infected Broiler chicks. One hundred and forty Broiler chicks -one day old- were randomly divided into two groups. The first group was kept as a control group. The second group was inoculated with S. Gallinarum biovar Gallinarum at a dose 0.2ml of sterile saline containing 3×108 CFU/ml through crop gavage. After inoculation, all experimental birds were kept under strict daily observation for recording clinical signs and mortality rate. Tissue samples were collected from dead and sacrificed chicks of each group at the 12th h, 1st, 2nd, 3rd, 4th, 7th, 14th, 21st and the 28th day post infection (dpi). Postmortem examination revealed severe congestion of internal organs. Microscopical findings illustrated congestion, thrombosis, focal hemorrhages, aggregation of bluish masses of bacterial colonies scattered in the hepatic parenchyma and thickening of hepatic capsule with bile duct hyperplasia. Fibrinous and granulomatous pericarditis were seen. Pulmonary congestion and thrombosis with focal hemorrhages and enteritis with desquamation of villar epithelium and goblet cells activation were observed. In conclusion, experimental inoculation of chicks with S. Gallinarum biovar Gallinarum was characterized by early septicemic lesions followed by perihepatitis, serofibrinous pericarditis and enteritis appeared after the 2nd dpi.