Objective: The aim of this study was to determine the association between serum albumin and the severity of microvascular complications and presence of coronary artery disease in type 2 diabetic patients. Patients and Methods: The presence of diabetic complications was assessed in a total of 130 Japanese patients with type 2 diabetes mellitus. Retinopathy was classified as absent, simple or proliferative diabetic retinopathy. Neuropathy was considered to be present when the patient showed absence of Achilles tendon reflex, and also evaluated by measuring the median motor nerve conduction velocity (MNCV) in the nerve conduction study. Results: In relation to retinopathy, there were 83 patients with no retinopathy (absent), 26 with simple retinopathy and 21 with proliferative retinopathy. There was a significant difference in the serum albumin level between the "absent" group and the other two groups. In relation to nephropathy, there were 68 patients with no evidence of nephropathy, 49 with microalbuminuria and 13 with proteinuria. The results of logistic regression analysis with adjustment for three variables (age, gender, serum CRP) revealed that serum albumin was independently related to proliferative retinopathy and proteinuria. In relation to neuropathy, serum albumin was found to be significantly related to the absence of Achilles tendon reflex, MNCV, and MFWL. The results of multiple regression analysis with adjustment for three variables (age, gender, serum CRP) revealed that serum albumin was independently related to MNCV and MFWL. Conclusions: Serum albumin was significantly associated with the severity of retinopathy and neuropathy.