The aim of this study was to provide evidence on the application of Research Electronic Data Capture for collecting repeated data during a 7-day period among older adults. Fifty-seven adults (≥50 years) with type 2 diabetes were recruited. Participants completed one sleep diary upon awaking and one self-care diary before going to bed each day for 7 days. The diaries were administered via the Research Electronic Data Capture Web-based system and were completed via participants’ own electronic devices. Objective compliance rate, time used to complete each diary, and participant experience were described. Approximately 80% (n = 45) of the participants used Research Electronic Data Capture. Among these participants, the noncompliance rate ranged between 0% and 8.9% for the sleep diary and 0% and 13.1% for the self-care diary. Participants spent 4.2 to 8.7 minutes on the sleep diary and 3.5 to 7.1 minutes on the self-care diary. It took the participants a longer time to complete the diaries during the first day than during the following 6 days. Few participants reported technical issues or felt inconvenient or stressful with completing the Research Electronic Data Capture diaries. Overall, the compliance rates were high. Completing the diaries was not time-consuming and participants were largely satisfied with the Research Electronic Data Capture data collection. Research Electronic Data Capture has aided the longitudinal data collection. With adequate training, Research Electronic Data Capture is an efficient tool to collect repeated data among older adults and thus is recommended for future research.