BACKGROUND: Enzyme replacement therapy (ERT) for Gaucher′s disease with alglucerase or imiglucerase is efficacious, well-tolerated and safe. However, cost considerations, visits to medical facilities, potentially duration of theray for life, are issues of major concern to a proportion of treated patients and has, in some cases, led to the withdrawal of therapy. AIMS: To elucidate whether an extension of the interval between enzyme infusions to once every three weeks is as effective in maintaining the clinical responses achieved with the bi-monthly regimen. MATERIALS AND METHODS: Four patients with an optimal response to ERT (at 30 units/kg every two weeks for an average of 27 months), were subjected to enzyme dose/frequency changes that essentially constituted a reduction in cumulative dose over the treatment period. Patients were assessed every 6 months for alterations in haematological parameters, plasma chitotriosidase levels, liver and spleen size, and bone symptoms. RESULTS: All patients had to resume the previous infusion schedule of once every two weeks; one because of new bone marrow infiltrates, two because of visceral enlargement, and the fourth due to progressive anaemia. CONCLUSIONS: This limited experience suggests that a reduction in enzyme dose associated with an extended interval between infusions may lead to variable disease control, and underscores the need for individualization of enzyme therapy.