Background: There is uncertainty about the best treatment option for children/adolescents with uncontrolled asthma despite inhaled corticosteroids (ICS) and international guidelines make different recommendations. We evaluated the pharmacological treatments to reduce asthma exacerbations and symptoms in uncontrolled patients age <18 years on ICS., Methods: We searched MEDLINE, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Embase, Web of Science, National Institute for Health and Care Excellence Technology Appraisals, National Institute for Health and Care Research Health Technology Assessment series, World Health Organization International Clinical Trials Registry, conference abstracts and internal clinical trial registers (1 July 2014 to 5 May 2023) for randomised controlled trials of participants age <18 years with uncontrolled asthma on any ICS dose alone at screening. Studies before July 2014 were retrieved from previous systematic reviews/contact with authors. Patients had to be randomised to any dose of ICS alone or combined with long-acting β 2 -agonists (LABA) or combined with leukotriene receptor antagonists (LTRA), LTRA alone, theophylline or placebo. Primary outcomes were exacerbation and asthma control. The interventions evaluated were ICS (low/medium/high dose), ICS+LABA, ICS+LTRA, LTRA alone, theophylline and placebo., Results: Of the 4708 publications identified, 144 trials were eligible. Individual participant data were obtained from 29 trials and aggregate data were obtained from 19 trials. Compared with ICS Low, ICS Medium+LABA was associated with the lowest odds of exacerbation (OR 0.44, 95% credibility interval (95% CrI) 0.19-0.90) and with an increased forced expiratory volume in 1 s (mean difference 0.71, 95% CrI 0.35-1.06). Treatment with LTRA was the least preferred. No apparent differences were found for asthma control., Conclusions: Uncontrolled children/adolescents on low-dose ICS should be recommended a change to medium-dose ICS+LABA to reduce the risk for exacerbation and improve lung function., Competing Interests: Conflict of interest: The authors have no potential conflicts of interest to disclose., (Copyright ©The authors 2023.)