Objective: To assess the budget impact of reimbursing aliskiren (Tekturna/Rasilez), the first drug from a new class of antihypertensive drugs (direct renin inhibitors), for the management of essential hypertension, from the health care payer (RIZIV/INAMI), patient, and societal perspectives in Belgium. Methods: Following ISPOR's budget impact guidelines, the pharmacy costs of the current therapy distribution of patients treated for essential hypertension in Belgium was compared to an alternative scenario, where aliskiren gains market share from conventional ARB therapy over a 3-year time horizon. IMS databases and literature data were used to estimate the total number of treated hypertensive patients and to derive market shares of the different antihypertensive medication classes (Beta-blocker, CCB, Diuretic, ACEi, ARB) and all possible dual and triple combinations thereof. The antihypertensive market share uptake of aliskiren was assumed to be identical to that observed previously for telmisartan in Belgium (0.16% year 1; 0.24% year 2; and 0.28% year 3). Only drug acquisition costs (obtained from official Tariffs) were considered in this analysis. Univariate sensitivity analyses were performed as well as sub-populations analyses. Results: The predicted Belgian populations treated for hypertension in 2008, 2009, and 2010 were estimated at 1,398,446 patients; 1,426,137 patients; and 1,525,827 patients, respectively. Over 3 years, it was estimated that RIZIV/INAMI hypertension drug budget following aliskiren reimbursement would increase by 0.02% (i.e. €148,395), from €755,522,606 to €755,671,001. Patients' co-payments would decrease by €20,613, resulting in societal incremental costs of €127,782. Sensitivity analyses confirmed that the net budget impact would remain of the same magnitude. Conclusion: Our analyses suggest that, under current assumptions, reimbursing aliskiren in Belgium would only slightly increase costs from the RIZIV/INAMI and societal perspectives, while generating savings for patients. Moreover, this budget impact does not consider aliskiren potential savings due to end organ protection.