Typically conducted by telephone, routine enteric disease case interviews are critical for foodborne illness surveillance, outbreak detection, and disease control. However, an increasing case load, along with the increased use of mobile telephones, has made case interviews more challenging to complete. For this reason, the Colorado Integrated Food Safety Center of Excellence developed and evaluated a pilot program using online surveys to supplement routine telephone-based enteric disease case investigations. From April to September 2019, investigators offered laboratory-confirmed Giardia cases from three Colorado counties the option of either a telephone interview or an online survey. The paper-based Giardia case investigation form was mapped to an online survey in Research Electronic Data Capture. We evaluated the pilot project response rates, timeliness, data quality, demographics, and user feedback. Of the 32 Giardia cases contacted, 66% requested the online survey, and of these, 81% completed the survey. Online survey cases were slightly younger (median: 42 vs. 48 years) and the majority agreed that the survey was easy to use (93%), did not take too much time (87%), and was easy to understand (67%). Staff time decreased for online surveys compared with telephone interviews (median: 6 vs. 19 min); however, the time from case report to interview completion doubled (median: 4 vs. 2 d for telephone interview cases) and data quality decreased slightly. Given limited public health agency resources, supplementing telephone interviews with online surveys may increase the efficiency of routine enteric case investigations. The results of this pilot project indicate online surveys are popular with enteric disease cases and substantially reduce staff time. Methods to improve the timeliness and data quality of online surveys should be explored to reduce the impact on disease control and outbreak detection activities.