Misunderstandings about the structure of microcredit interest rates continue to generate rich criticism of the industry's high interest rates. Research has focused attention on the cost structure of interest rates and, more recently, on macroeconomic and macro‐institutional factors. While the cost structure is probably the most important determinant of interest rates, other factors also matter. In addition to other important results that usually validate the empirical literature, this paper finds that microcredit interest rates respond positively to corruption. The analysis shows that there is asymmetry between the effects of corruption, depending on whether or not the MFIs are regulated. While corruption has a positive and significant impact on interest rates of unregulated MFIs, it has a negligible impact on interest rates of regulated MFIs.