Parenteral artesunate has been shown to be a superior treatment option compared to parenteral quinine in adults and children with severe malaria. Little evidence, however, is available on long-term safety. Recently, cases of late-onset haemolysis after parenteral treatment with artesunate have been reported in European travellers with imported Plasmodium falciparum malaria. Therefore, an extended follow-up of adult patients treated for severe imported malaria was started in August 2011 at the University Medical Center Hamburg-Eppendorf. Until January 2012, three patients with hyperparasitaemia (range: 14-21%) were included for analysis. In all three patients, delayed haemolysis was detected in the second week after the first dose of intravenous artesunate. Reticulocyte production index remained inadequately low in the 7 - 14 days following the first dose of artesunate despite rapid parasite clearance. Post-treatment haemolysis after parenteral artesunate may be of clinical relevance in particular in imported severe malaria characterized by high parasite levels. Extended follow-up of at least 30 days including controls of haematological parameters after artesunate treatment seems to be indicated. Further investigations are needed to assess frequency and pathophysiological background of this complication.