Follow-up methods must be easy for young people to handle. We examine Interactive Voice Response (IVR) as a method for collecting self-reported data. Sixty inpatients were recruited from a child and adolescent psychiatric emergency unit in Malmö, Sweden and called every second (N = 30) or every fourth (N = 30) day from discharge until first visit in outpatient care. A pre-recorded voice asked them to evaluate their current mood using their mobile phones. Average response rate was 91%, and 71% had a 100% response rate. Gender, age and length of inpatient treatment did not affect response rate, nor did randomisation. Boys estimated their current mood on average as 3.52 units higher than girls, CI = (2.65, 4.48). Automated IVR is a feasible method of collecting follow-up data among adolescents discharged from a psychiatric emergency unit.