The aim of this study was to investigate serum lipoprotein(a) [Lp(a)], homocysteine and malondialdehyde (MDA) levels in NIDDM (type 2) patients with and without complications. A total of 49 NIDDM patients diagnosed with diabetes mellitus with mean age of 56±9 were included to this study. Control group was composed of 14 healthy volunteers. Group I consisted of 33 NIDDM patients with complications while group II consisted of 16 patients without complication. There was a statistically significant difference in homocysteine, lp(a) and MDA levels between group I and group II (p<0.05). While serum homocysteine, Lp(a) and MDA levels of group I were 28.7± 7.4 µmol/L, 34± 7.7 mg/dl, 1.8± 0.5 nmol/ml, in group II these levels were determined to be 19± 6.3 µmol/l, 17 ± 8.4 mg/dl, 1.05 ± 0.38 nmol/ml, respectively. Serum homocysteine, lp(a) and MDA levels significantly increased in diabetic patients with complication (p<0.05). In diabetic patients a positive correlation between serum homocysteine, lp(a) and MDA levels was determined. Serum homocysteine, lp(a) and MDA levels might be useful criteria for evaluating prognosis in patients when diabet is not properly monitored for control of glycemia.