Abstract: In this study we explored the relationship between the serum levels of the inflammatory factors tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and endothelin-1 (ET-1) and the severity of diabetic nephropathy (DN). The study included 50 type 2 diabetics with various degrees of nephropathy (20 patients with normoalbuminuria, 15 with microalbuminuria and 15 with macroalbuminuria) compared to 17 healthy volunteers. ELISA technique was used to measure the serum levels of these inflammatory factors. Significant increase in the serum levels of TNF-α and IL-6 were observed in diabetic patients compared to control subjects and this increase was in concert with the progression of renal disease as indicated by urinary albumin excretion (UAE). Regarding ET-1, serum levels were higher in micro- and macroalbuminuric patients as compared to normoalbuminuric patients and control subjects. ET-1 was significantly positively correlated with both TNF-α (r = 0.595, p<0.01) and IL-6 (r = 0.739, p<0.01). These results suggest that the inflammatory factors; TNF-α, IL-6 and ET-1 are associated with DN and may have some etiopathogenic roles in disease development.