Omalizumab has been shown to reduce exacerbation rates in moderate to severe allergic asthma. Our aim was to evaluate omalizumab efficacy and safety in a real-life setting in severe asthmatic children. 104 children (aged 6-18 years), followed up in paediatric pulmonary tertiary care centres, were included at the beginning of omalizumab treatment. Asthma control levels, exacerbations, inhaled corticosteroid dose, lung function and adverse events were evaluated over 1 year. Children were characterised by allergic sensitisation to three or more allergens (66%), high IgE levels (mean 1125 kU · L(-1)), high rate of exacerbations (4.4 per year) and healthcare use during the previous year, and high inhaled corticosteroid dose (mean 703 μg equivalent fluticasone per day). Asthma control levels defined as good, partial or poor, improved from 0%, 18% and 82% at entry to 53%, 30% and 17% at week 20, and to 67%, 25% and 8% at week 52, respectively (p<0.0001). Exacerbation and hospitalisation rates dropped by 72% and 88.5%, respectively. At 12 months, forced expiratory volume in 1 s improved by 4.9% (p=0.023), and inhaled corticosteroid dose decreased by 30% (p<0.001). Six patients stopped omalizumab for related significant adverse events. Omalizumab improved asthma control in children with severe allergic asthma and was generally well tolerated. The observed benefit was greater than that reported in clinical trials.