A 9 year old sahiwal cow as subitted for postmortem following death in a farm housing 100 animals of various breeds of India. Grossly, the animal showed subcutaneous adipose tissue gelatinisation and oedema with streaks of haemorrhage in the submaxillary space, pharyngeal region, neck, dewlap and brisket region. Fibrinous adhesions between the pericardium of heart and ventral aspect of lungs. Thoracic cavity revealed yellow fluid with fibrin shreds. Pericardial sac showed thickening with thick dirty white fluid. Samples collected from different organs were cultured followed by multiplex and species specific Polymerase chain reaction which consistently showed Mannheimia haemolytica in all the organs. Histopathology showed that the alveolar spaces were diffusely filled with sero-fibrinous exudates admixed with neutrophils and red blood cells. Interlobular septa were thickened and markedly distended with fibrinous exudation. None of the other animals housed showed and symptom or mortality. This isolated case of mannheimiosis could be due to unknown stress which has led to the multiplication of the organism leading to death of the animal.