Avian adenoviruses are diverse group of pathogens and recently hydropericardium hepatitis syndrome (HHS) Is an important, emerged disease of poultry. Particularly 2-3 weeks old age broilers increased mortality ranging from 20-30% and brown native chicken 3-7 weeks sudden onset with mortality 20-50%, typically development secondary infection. The infection chicken shows liver enlarged, pale and straw- colored fluid is present in the sac surrounding the heart. Histopathological positive samples have necrotic foci and basophilic intranuclear inclusion bodies in the hepatocytes and polymerase chain reaction (PCR) was useful for detect the fowl adenovirus (FAV) associated with HHS.