Introduction: Collecting patient-reported follow-up data for prospective studies in the emergency department (ED) is challenging in this acute care, minimal continuity setting. Follow-up is frequently attempted using telephone contact and in some instances mail correspondence. The objective of this study was to determine if text messaging study participants involved in an ongoing randomized trial resulted in a lower rate of attrition as compared to conventional telephone follow-up. Methods: This was a secondary analysis of research participants enrolled in a randomized controlled trial assessing head injury discharge instructions. Adult (18-64 years) patients presenting to an academic ED (annual census 65,000) with chief complaint ‘head injury’ occurring within 24 hours of ED visit were contacted by telephone 2 and 4 weeks post ED visit to complete a symptom questionnaire. During the first 4 months of study follow-up, participants were contacted by a conventional telephone call. Attrition was higher than anticipated, thus we received subsequent ethics approval for the final 3 months of follow-up duration to contact participants by text message on the day of the first telephone attempt as a reminder of the telephone interview scheduled later that day. The proportion of patients lost to follow-up at 2 and 4 weeks post ED visit was compared between participants not receiving and receiving reminder text messages. Results: 118 patients were enrolled in the study (78 underwent conventional follow-up and 40 received text messages). Mean (SD) age was 35.2 (13.7) years and 43 (36.4%) were male. During the period of conventional follow-up, 3 participants withdrew from the study. Of the remaining 75 participants, 24 (32.0%) at 2 weeks and 32 (42.7%) at 4 weeks were unable to be contacted. Of the 40 participants receiving a reminder text message, 4 (10.0%) at 2 weeks and 10 (25.0%) at 4 weeks were unable to be contacted. Overall, text messaging study participants decreased attrition by 22% (95% CI: 5.9%, 34.7%) and 17.7% (95% CI: -0.8%, 33.3%) at 2 and 4 week follow-up, respectively. Conclusion: In this young ED cohort participating in a randomized trial, text message reminders of upcoming telephone follow-up interviews decreased the rate of attrition. Text messaging is a viable, low-cost communication strategy that can improve follow-up participation in prospective research studies.