This paper examines the competitive effects of recent commercial bank entry into the corporate debt underwriting market. In particular, the effects of bank entry on underwriter spreads, ex-ante yields, and market concentration. We find that underwriter spreads have declined significantly with bank entry, consistent with the market becoming more competitive. This effect is strongest among lower-credit rated and small-sized debt issues where banks have underwritten relatively more issues. We find a similar decline for ex-ante yields. The early evidence also indicates that bank entry has tended to decrease market concentration. Overall, our results suggest that bank entry has had a favorable pro-competitive effect.