In this article, we review the literature on the best ways to identify the causal effects of microcredit, present, and discuss some empirical results of the impact of microcredit on the adoption of innovations, investments, farm incomes, and profits. The results of empirical studies converge toward a positive impact of access to microcredit on the adoption of agricultural technology and investment. In terms of the effect on the technical efficiency of farms, agricultural income and profit, and consumption, the results do not all point in the same direction. The effects of microcredit are likely to vary depending on the context of the study.