With the growing popularity of smartphones and tablet PCs (tablets) equipped with mobile browsers, the possibilities to administer surveys via mobile devices have expanded. To investigate the possible mode effect on answer behavior, results are compared between a mobile device–assisted web survey and a computer-assisted web survey. First, a premeasurement in the CentERpanel is conducted to analyze the user group of mobile devices. Second, the users are randomly allocated one of the three conditions: (1) conventional computer-assisted web survey, (2) hybrid version: a computer-assisted web survey with a layout similar to mobile web survey, and (3) mobile web survey. Special attention is given to the design of the mobile web questionnaire, taking small screen size, and typical functionalities for touchscreens into account. The findings suggest that survey completion on mobile devices need not lead to different results than on computers, but one should be prepared for a lower response rate and longer survey completion time. Further, the study offers considerations for researchers on survey satisfaction, location during survey completion, and preferred device to access Internet. With adaptations, surveys can be conducted on the newest mobile devices, although new challenges are emerging and further research is called for.