Despite organizations’ widespread Internet use and ready availability of Web survey software, few studies have examined explicitly the impact on employees’ responses of using the Web as opposed to mail-based surveys (MBS). This article addresses this gap using an employee attitude survey distributed to a 50% systematic sample of 3,338 employees by mail, the remaining employees receiving the survey via a Web link. Although the return rate for the Web (49.1%) was higher than for mail (33.5%), the quality of Web returns was reduced by a higher number of partial responses and abandonments. Taking into account effect size, significant differences in response were small other than for open question content. Recommendations regarding use of Web-based surveys (WBS) are offered and areas for future research suggested.