Chemotherapy induces immunosuppression which is associated with a significant increase in the frequency and severity of infections. Neutropenia is the most important factor in determining susceptibility to bacterial infections. Our aim was to establish the prevalence of bacterial infections and bacterial susceptibility patterns in patients with fever, neutropenia and hematological neoplasias. Cultures were obtained prior empirical antimicrobial treatment. Susceptibility tests to antibiotics were performed for all microorganisms considered pathogens. Descriptive statistics were used for each variable. Differences between proportions were estimated by means of χ2 or Fisher's exact test. We included 85 patients.Primary bacteremia was the most frequent cause of fever (52%). Microorganisms most frequently isolated were:S. epidermidis (54.2%), E. coli (12.5%), S. aureus (8.3%). In susceptibility tests 88.5% of S. epidermidis strains were resistant to oxaciline (MIC > 8 μ/ml); E. coli was resistant to ceftazidime (50%) and trimethroprim/sulfamethoxazole (83%).In conclusion, gram-positive microorganisms are predominant in patients with fever and neutropenia followed by gram-negatives like E. coli. Predominance of gram-positives microorganism forces us to reconsider our current prophylactic and therapeutic antimicrobials regimens used in these patients.