This study provides first empirical evidence on the impact of entrepreneurs' financial knowledge on borrower discouragement. Using novel survey data on Italian micro-enterprises, we find that less financially knowledgeable entrepreneurs are more likely to be discouraged from applying for new financing, due to higher application costs and expected rejection. Our main results are robust to several sensitivity checks, including accounting for potential endogeneity. Furthermore, we show that the observed self-rationing mechanism is rather inefficient, suggesting that financial knowledge might play a key role in reducing credit market imperfections.