Two studies comparing the cost-effectiveness of irbesartan to similar blood pressure control with standard antihypertensive medications (excluding angiotensin-converting enzyme inhibitors and other angiotensin receptor blockers) in treatment of patients with hypertension, type 2 diabetes, and microalbuminuria have been published to date; one in a United States setting, the other in a Spanish setting. Both studies were based on a Markov-based Monte Carlo simulation model, with the effects of irbesartan or standard blood pressure control taken from the Irbesartan Reduction of Microalbuminuria-2 (IRMA-2) and the Irbesartan in Diabetic Nephropathy Trial (IDNT) clinical trials. In both Spanish and U.S. settings, irbesartan was projected to delay the onset of end-stage renal disease (ESRD), reduce the cumulative incidence of ESRD, increase life expectancy, and reduce overall direct medical costs. Irbesartan treatment of patients with type 2 diabetes, hypertension, and microalbuminuria may lead to major improvements in long-term patient outcomes, with substantial cost savings as an added bonus to third party payers.