The purpose of this paper is to examine the determinants of firms switching the lead underwriter they use to underwrite their first and second public issues of corporate bonds in Japan between 1994 and 2002. A probit model which has as its dependent variable a 0-1 dummy variable taking the value one if the issuer switches lead underwriters, and zero otherwise, is used to analyze this problem. It is found that the probability of switch of underwriters between the first and second issues is significantly increased if the securities company subsidiary of a bank was the initial underwriter or the reputation of the underwriter of the initial underwriter worsens between the initial and the second issue. Evidence is also presented that suggests underwriters who can increase the degree of overpricing of the initial issue are more likely to be chosen to act as the underwriter of the second issue. Despite the theoretical suggestions that underwriting involves investment in durable firm-specific assets which might lead to initial issuers having an inside edge in being chosen to underwriter the second evidence, there is some weak evidence to suggest that switching of underwriters occurs when second issues are made relatively quickly after the first issue.