Aim: Fibrinogen is an inflammatory marker which is an acute phase protein, plays a key role in the pathogenesis of atherosclerosis and complication of atherothombosis disease. Pathogenesis of type 2 diabetes mellitus is closely related with acute phase response which is predominately mediated by cytokine. By estimating circulating fibrinogen in type 2 (T-2) and type1 (T-1) diabetic patients, I tried to establish this hypothesis. Method: Freshly diagnosed twelve T-1 cases, twenty-five T-2 cases and twenty-five Type-2 cases under oral hypoglycemic agent for at least 5 years were selected and were estimated the level of fibrinogen. Thirty normal controls were also selected. Result: Freshly diagnosed T-1 and Type-2 cases showed significantly higher levels of the fibrinogen in compare to control. T-2 cases had slightly elevated values of fibrinogen in compared to the T-1 cases. There are no significant change of fibrinogen level is found in T-2 cases after treating by oral hypoglycemic drugs in compare of T-2 cases. Conclusion: By evaluating the plasma level of fibrinogen in different categories it can be postulated that a low grade inflammatory process is definitely implicated in the pathogenesis of both type 1 and type 2 cases. This line of pathological basis should be further explored for diagnosis, management and follow up.