Introduction Electronic ecological momentary assessment (EMA) can provide precise information regarding day-to-day functioning of patients overcoming some of the limitations of usual clinical evaluation; however adherence to this methodology might be a major threat. Research and application of EMA concerning clinical settings remains scant. Our goal was to study the user profiles of EMA in a clinical sample of adolescents. Material and methods 209 adolescents following an outpatient mental health treatment accepted to use EMA. They were evaluated in different sociodemographic and clinical variables as well as the use that they made of EMA. Results 39.7% of patients were considered users and 60.3% non-active users. Certain self-harm behaviours were more common in the group of active users, while hyperkinetic disorders were more common in the group of non-active users. A regression analysis revealed that non-suicidal self-injury (OR = 2.99) and hyperkinetic disorders (OR = 0.51) were related to the use of EMA. Conclusion This preliminary study adds novel and promising information about EMA use in clinical practice. Adolescents with self-harm behaviours EMA seem more prone to use this tool. Our study provides support for actively monitoring self-harm behaviours with EMA. Future studies might consider a comprehensive analysis of adherence and EMA data collection.