Background Diabetic retinopathy (DR) is a major microvascular complication of diabetes. Aim of the work To study the association between serum apolipoprotein B (Apo-B) and DR in type 2 diabetes. Patients and methods This comparative study was conducted on 75 patients with type 2 diabetes recruited from the Endocrinology and Ophthalmology Departments of Al-Zahraa University Hospital. They were divided into three groups according to DR grading: group A included 31 patients without DR, group B included 27 patients with nonproliferative DR, and group C included 17 patients with proliferative DR. Detailed history, clinical examination, and anthropometric measurements were assessed for all selected patients. Fasting and 2-h postprandial blood glucose levels, glycosylated hemoglobin, total cholesterol (CHO), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and Apo-B were measured. Fundus examination was done for all participants. Results CHO, TGs, LDL-C, and Apo-B were statistically significantly higher in group C followed by group B and then group A. However, HDL-C was statistically significantly lower in group C followed by group B and then group A. A significant positive correlation was found between DR on one hand and age, diabetes duration, systolic blood pressure, diastolic blood pressure, glycosylated hemoglobin, CHO, TGs, LDL-C, and Apo-B on the other hand. DR correlated negatively with HDL-C. Conclusion Serum Apo-B levels may be a strong biomarker for DR than traditional lipids.