Eculizumab is currently the only approved treatment for atypical haemolytic uraemic syndrome (aHUS), but data in paediatric patients are limited. Recent findings from a prospective phase II study in 22 children with aHUS suggest that eculizumab is safe and efficacious in this setting. After 26 weeks of treatment, 14 patients had a complete thrombotic microangiopathy response, 18 patients showed normalization of haematological parameters and 16 patients had a ≥25% decrease in serum creatinine levels from baseline. No serious adverse events related to eculizumab therapy were reported.