Background: Remote monitoring-enabled insertable cardiac monitors (ICMs) are useful tools for arrhythmias and symptom management. This study sought to evaluate the outcome of ICM implantation in a large, heterogeneous cohort of pediatric and young adult patients. Methods: Single centre, retrospective analysis of patients who underwent ICM implantation in 2010–2019. Patients were analysed according to age, symptoms, arrhythmias and underlying heart disease. Results: A total of 200 consecutive patients (58% male), aged 11.5 \pm 5.8 years at ICM implantation, were included. Follow-up was 31 \pm 18 months. Electrophysiologic study (EPS) was initially performed in 123 patients and was negative in 85%. Patients had no heart disease (57.5%), congenital heart defects (21%), channelopathies (14.5%), cardiomyopathies/heart tumors (8%). The commonest symptoms were syncope/presyncope (45.5%) and palpitations (12.5%). A definite diagnosis was made in 63% of patients (positive diagnosis in 25%, negative in 38%) after 8 (2–19) months of monitoring. EPS results and the presence/absence of an arrhythmia before ICM implantation had no impact on the diagnostic yield. Symptomatic patients as well as patients without structural heart disease showed higher diagnostic yield. Patients with a positive diagnosis underwent pacemaker/implantable cardioverter-defibrillator implantation (13%), pharmacological treatment (10.5%), or catheter ablation (1.5%). Conclusions: In a large cohort of 200 children and young adults, ICMs with remote monitoring showed a high diagnostic yield (63%), especially in symptomatic patients and in patients without structural heart disease.