Using audit hours by rank-specific in Korean listed firms from 2014 to 2019, we examine whether there is the effect of audits effort on the credit ratings (RATING) and the cost of debt (COD), and investigate how audit effort mediates relationship between ROA and RATING (or COD). Specifically, we analyze whether external information users (i.e., credit rating agencies and creditors) perceive increase in auditor’s effort (i.e., rank-specific audit hours, total audit hours) as a proxy for audit quality or audit risk. Overall, our results provide some evidence that the market reacts negatively to more audit hours, and the results imply that market participants perceive that more audit effort is associated to firms with the higher audit risk. We also find that the effect of more audit hours weaken the positive relation between ROA and RATING or negative relation between ROA and COD. We also find that the frequency of auditor’s communication with corporate governance is negatively (positively) associated to RATING (or COD). Thus, this study contributes to the literature on audit quality/risk by showing novel evidence that the announcement of more audit hours are perceived a proxy for audit risk rather than audit quality from rating agencies and creditors.