According to proponents, voluntary agreements (VAs) negotiated with polluters sidestep weak institutions and other barriers to conventional environmental regulation in developing countries. Yet little is known about their effectiveness. We examine VAs in Colombia, a global leader in the use of these policies. We find that the main motive for using VAs has been to build capacity needed for broader environmental regulatory reform. Their additional effect on environmental performance has been questionable. These findings suggest that in developing countries, VAs may be best suited to capacity building, not environmental management per se.