During the Cold War, U.S. foreign policy was dominated by the strategic priority to contain Soviet Union. In the post-Cold War era, the expansion of democracy as foreign policy concerns became prominent. To what extent does U.S. aid reflect a concern for democracy? As a foreign policy instrument, does U.S. democracy & governance assistance make a systematic impact on the level of procedural democracy of developing countries? The systematic and coherent understanding of the impact of the U.S. aid on the level of procedural democracy of developing countries are still poorly understood and remains elusive. I examine the empirical linkage between U.S. democracy aid and the procedural democratization of developing countries for the years 1990-2005. I disaggregate aid separating democracy & governance assistance from other forms of assistance to assess the impact of democracy aid on democratization. Using Simultaneous Equation model, I estimate the determinants of aid at the initial selection stage and the subsequent impact of aid on procedural democratization. The data demonstrate that in the post-Cold War period, democracy assistance exerts a meaningful positive impact on the level of procedural democracy. On the other hand, empirical findings show that assistance of National Endowment for Democracy and general economic aid are marginal predictors of the improvement of procedural democratization.