Hyperglycemic diabetic have a deficit in their non-specific defense. The present study investigated phagocytosis of Nitrobluetetrazolium in 62 diabetic patients with age between (5-70) years, and with variable disease period (1-20) years of both sex; (31) of them are IDDM, other are NIDDM. All patients were divided in two groups depending their glucose level (more 200mg/dl) and (less than 160mg/dl) and were compared with control. The results indicated a significant reduction in phagocytic activity in all diabetic patients, moreover a significant reduction (p≤0.05) in phagocytic activity in both IDDM, NIDDM. On the other hand a significant reduction in phagocytic activity in the two groups of IDDM, NIDDM (glucose level more than 200mg/dl) and (160mg/dl) when compared with control. The study suggests that all diabetics have a significant reduction in their phagocytic activity, and this reduction is not related to the type of disease, age, sex, but depending on the glucose level in blood.