Childhood Takayasu’s arteritis (c-TA) is scarcely reported but is characterized by devastating morbidity and mortality. This study aims to investigate the clinical course of c-TA and prognostic factors associated with rehospitalization and events including vascular complications, flares, and death. An ambispective study of 101 c-TA patients satisfying the American College of Rheumatology (ACR) criteria and/or the European League against Rheumatism (EULAR)/Pediatric Rheumatology International Trials Organization (PRINTO)/Pediatric Rheumatology European Society (PReS) criteria was conducted from January 2002 to December 2017. Data on demographic, clinical, laboratory, imaging, and therapeutic features were collected. Event-free survival, complication-free survival, flare-free survival, rehospitalization-free survival, and associated prognostic factors were assessed by Kaplan-Meier survival curve and propensity score analysis. The median age at c-TA onset was 14 (interquartile range (IQR) 12–16) years and 76.2% were female. Hypertension (70.3%), blood pressure discrepancy (55.4%), bruits (51.5%), and pulse deficits (37.6%) were core presentations. Major vascular involvement included the renal artery (62.4%), abdominal aorta (42.6%), subclavian artery (43.6%), and carotid artery (42.6%). Glucocorticoids (78.2%), antihypertensive drugs (72.3%), antiplatelet agents (72.3%), and revascularization (57.4%) were made up the majority administered. At a median 2.4 (IQR 0.7–6.1) years of follow-up, events, rehospitalization, vascular complications, flares and death were observed in 44.6%, 37.6%, 44.6%, 26.7%, and 3%, respectively. The 5-year event-free survival, rehospitalization-free survival, vascular complication-free survival, and flare-free survival were 42.8%, 55.8%, 45.9%, and 62.3%, respectively. Body mass index (BMI) (hazard ratio (HR) = 0.49, 95% confidence interval (CI) 0.30–0.81, p = 0.005), stroke (HR = 7.37, 95% CI 2.35–23.1, p = 0.001), and revascularization (HR = 0.51, 95% CI 0.27–0.94, p = 0.032) were independent prognostic predictors of events. Predictors for rehospitalization include age at admission (HR = 0.81, 95% CI 0.69–0.94, p = 0.006), renal artery involvement (HR = 0.49, 95% CI 0.25–0.96, p = 0.037), and elevated C-reactive protein (CRP; HR = 2.50, 95% CI 1.24–5.00, p = 0.01). BMI level (p = 0.024) and renal artery involvement (p = 0.015) were also associated with vascular complications, while revascularization (p = 0.002) independently correlated with re-flares. This large ambispective study of c-TA revealed an early 3% mortality at the first year and around 50% morbidity within 5 years after diagnosis. Hypertension, renal artery involvement, and revascularization based on anti-inflammation, antihypertension, and antiplatelet medications dominated c-TA with indications for optimistic prognosis. Patients with initial lower BMI level, a younger age at admission, stroke, and elevated CRP have a high risk of poor outcomes, requiring close c-TA monitoring and more aggressive management. NCT03199183 , unique protocol ID: 2016-ZX43. June 26, 2017