Although the clinical practice guidelines recommend continuous adjustment of asthma treatment and reducing the maintenance drugs when achieving control (step-down), there are few studies of standard clinical practice aimed at collecting information on the factors that determine step-down failure.To determine the factors that determine step-down failure in standard clinical practice of patients with moderate-severe asthma controlled by a combination of inhaled glucocorticoids and long-acting beta agonists.A multicentre retrospective study included 374 patients with moderate-severe asthma controlled with inhaled glucocorticoids and long-acting beta agonists for whom the physician indicated a step-down in 2016.The step-down failed in 41.7% of the patients. The following factors were related to failure: greater patient age (P=.006), presence of at least 2 comorbidities (P=.016), greater severity level (severe persistent vs. moderate persistent) (P.001), greater age at diagnosis (40 years) (P=.045), the higher the therapeutic step before (P=.003) and after the change (P.001), the shorter the time of improvement/control prior to the change (P=.019), lower FEVIn standard clinical practice conditions, step-down fails in a high percentage of patients, and the suggestion is to indicate step-down when the patient has had more than 6 months of disease control.