A total of 2142 patients with febrile neutropenia resulting from cancer chemotherapy were registered in two observational studies and followed prospectively in different institutions. There were 499 (23%) patients with bacteraemia who are reviewed here. The relative frequencies of Gram-positive, Gram-negative and polymicrobial bacteraemias were 57%, 34% and 10% with respective mortality rates of 5%, 18% and 13%. Mortality rates were significantly higher in bacteraemic patients than in non-bacteraemic patients; a trend for higher mortality was observed (without reaching statistical significance) in those patients in whom bacteraemia was associated with a clinical site of infection compared to bacteraemic patients without any clinical documentation. Prophylactic antibiotics but not granulopoiesis stimulating factors were associated with a lower incidence of Gram-negative bacteraemia; however, neither prophylactic approach influenced the subsequent rate of complications in the patients who developed bacteraemia. The present study also confirms that the MASCC scoring system can identify a group of bacteraemic patients with a relatively low risk of complications and death (MASCC >/=21). On the other hand, in patients with very low levels of the MASCC score (<15), and then with predicted very unfavourable risk, the rate of complications and death was dramatically high, irrespective of the microbiological nature of the bacteraemia.