This paper evaluates from a microeconomic perspective the lending cost determinants in the Peruvian banking system in the June 2004-December 2005 period. The evaluation considers the credit market segments identified in a prior study (published in 2002). Furthermore, it reviews the progress occurred in the financial system infrastructure –asymmetric information, credit risk assessing technologies, competitive structure, and credit guarantees performance– in the aforementioned period. The paper also contains a set of “study cases” that contributes to a better understanding of the credit market dynamics. We found evidence that supports the presence of a higher level of competition in every market segment, especially for that of corporate borrowers. Finally, the paper suggests a set of policies to further reduce the cost of credit.