Patients with neutropenia and fever conform a heterogeneous population with a variable risk of serious complications and mortality. The goal of this study was to identify prognostic risk factors present at the beginning of the episode, for adverse events and serious complications in patients admitted in a general ward with fever and neutropenia. A cohort of 238 episodes with neutropenia and fever (neutrophils < 1000/mm3 and T > 38.3 00) in 167 patients admitted to our general hospital between 1997 and 2004 was followed. Eighty two percent of the patients had hematologic malignancies, 14% solid tumors and 4% were not associated with chemotherapy. Sixty seven adverse events were registered (46% renal insufficiency, 27% refractory hypotension, 15% respiratory insufficiency and 12% major bleeding). Significant differences were found in presence of current co-morbidities, body temperature > 39 00, heart rate > 120 beats per minute, respiratory rate > 24 per minute, systolic blood pressure < 90 mm Hg, presence of 3 or more altered laboratory values, presence of a clinical site of infection and positive blood cultures. The logistic regression multivariate analysis showed that the following characteristics were independently associated with adverse events: systolic blood pressure < 90 mm Hg (OR = 7, p < 0.01), current co-morbidities (OR = 8.5, p = 0.02), respiratory rate > 24 per minute (OR = 2.8, p = 0.01), and the presence of a clinical site of infection (OR = 2.1, p = 0.03). The presence of systolic hypotension, high respiratory rate, current co-morbidities and a clinical site of infection at the time of admission were identified predictors of subsequent serious complications in patients admitted with fever and neutropenia in a general ward.