The immunosuppressive effect of allogeneic blood transfusions can be associated with a poor prognosis for cancer patients. Predeposit autologous blood transfusions could be a solution to overcome this putative deleterious effect. We performed a randomised clinical study to compare the effects of autologous with allogeneic blood transfusions in colorectal cancer patients. There was no significant difference in disease-free survival between both randomisation arms. However, the transfused patients had a significantly shorter disease-free interval as compared with the non-transfused patients. This association of transfusions with recurrent disease was only the case for local recurrences, whereas the incidence of distant metastases was unaffected. We conclude that the use of a predeposit autologous blood transfusion programme does not improve the prognosis in colorectal cancer patients. The negative association between blood transfusions and cancer recurrence is only true for local recurrences, which suggests that not the blood transfusions themselves but rather the circumstances necessitating them are the real predictors of prognosis.