Patients with end-stage renal disease (ESRD) who are on renal replacement therapy (RRT) usually have a certain number of comorbid factors. Cardiovascular diseases are the most common comorbidities and the most common causes of mortality in ESRD patients. Noncardiovascular comorbid factors including nutrition also have impact on survival of ESRD patients on RRT. There are scarce data regarding comorbidity in developing countries. Available data have shown that hypertension, diabetes, and various cardiovascular disorders are the leading comorbidities. Improvement in outcome for ESRD patients would depend on improving quality in RRT as well as a better understanding and management of comorbid conditions.