BACKGROUND Bloodstream infections are associated with a significant patient morbidity and mortality. The detection of microorganisms in the patients' blood has a great diagnostic and prognostic significance. The early positive results provide valuable diagnostic information, based on which the appropriate antimicrobial therapy can be initiated. OBJECTIVE To know the aetiology of the bloodstream infections in the Kathmandu Medical College, Nepal and the antibiotic sensitivity patterns of the causative organisms. METHODS The blood specimens which were received from May 2010 to October 2010 in Kathmandu Medical College and Teaching Hospital, Kathmandu, Nepal, were processed and all the positive isolates were included in the study. The isolates were identified by the standard laboratory procedures. The antibiotic susceptibility patterns were determined by the modified Kirby Bauer antibiotic sensitivity method. RESULTS Of the 1089 blood cultures which were received with the suspected cases of blood stream infections, 138 (12.6 %) were bacteriologically positive. Salmonella serotypes were isolated in 42.7% cases of blood stream infections, followed by Klebsiella pneumoniae in 19.5%, Staphylococcus aureus in 15.9% and others in the rest of the cases. All the gram-negative bacilli isolates showed lower degrees of resistance to amikacin and ofloxacin. All the gram positive isolates were sensitive to amikacin, oxacillin and vancomycin. CONCLUSIONS This study stresses on the need for a continued screening and surveillance in the routine blood culture technique for starting with the empiric therapy for blood borne infections.