Benhabib and Rustichini [Optimal taxes without commitment, J. Econ. Theory 77 (1997) 231-259] study the properties of optimal capital taxes in economies without commitment and no government debt. They find that capital taxes may be different from zero at steady state. This note shows that, once governments have the possibility of issuing debt and smoothing taxes over time, optimal steady state capital taxes turn out to be zero. (c) 2006 Elsevier Inc. All rights reserved.