Introduction Previous findings from a pragmatic trial suggest that usual care compared with usual care plus individualised homeopathy is not a feasible design to address homeopathic interventions for asthma. Objective The main purpose of this article was to investigate the feasibility of the randomised withdrawal design as a strategy to assess the effectiveness of a standardised clinical–pharmaceutical homeopathic protocol (Organon.modus) on perennial asthma in adolescents. Methods Randomised withdrawal, double-blind, parallel, placebo-controlled, 12-week study. Patients: 12 to 17 years old adolescents, with the diagnosis of perennial asthma, using inhalatory beclomethasone (plus fenoterol for wheezing episodes), who achieved 3 months of well-controlled asthma, after a variable period of individualised homeopathic treatment according to Organon.modus protocol. Setting: a secondary care medical specialist centre. Intervention: continuation with the individualised homeopathic medicine or with indistinguishable placebo during 12 weeks of beclomethasone step-down. Primary outcome: number of days of well-controlled asthma. Secondary measures: number of days of fenoterol use, number of visits to an emergency service (without hospitalisation) and percentage of patients excluded due to an exacerbation characterising a partly controlled asthma. Tolerability was assessed by Adverse Events, registered at every visit. Results Nineteen patients were randomised to continue treatment with homeopathy and 21 with placebo. Effectiveness measures for the homeopathy and placebo groups respectively were median number of days of good clinical control: 84 versus 30 (p = 0.18); median number of days of fenoterol use per patient: 3 versus 5 (p = 0.41); visits to an emergency room: 1 versus 6 (p = 0.35); percentage of exclusion due to partly controlled asthma: 36.8% versus 71.4% (p = 0.05). Few Adverse Events were reported. Conclusions This pilot study supports the feasibility of the double-blind randomised withdrawal design in studies investigating homeopathy on teenage asthma, when performed by specialists following a standardised clinical–pharmaceutical homeopathic protocol.