This report is concerned with the development of an hemolytic uremic syndrome (HUS) in 6 patients (3 males, 3 females, aged 53 to 73) suffering from an advanced cancer and treated by protracted (>= 4 months) infusions of gemcitabine. Over 4 to 14 months, the patients received 13-34 infusions delivering a cumulative dose oscillating between 9 and 29 g/m2. A progressive alteration of renal function preceeded the acute syndrome. After interruption of gemcitabine and symptomatic treatment, the evolution of haemolytic anemia was generally favourable. This was not the case for renal dysfunction: 2 complete and 1 partial resolution of renal insufficiency were noted, but 1 case required chronic dialysis. Based on the authors experience, the frequency of an HUS complication after protracted gemcitabine treatment could be as high as 2.7 %.