Patients admitted to the Intensive Care Unit (ICU) are at risk of developing life-threatening nosocomial infections, especially with organisms resistant to commonly used antibiotics. Neurosurgical patients are particularly vulnerable because of the serious nature of their illness, the frequency of associated trauma and the presence of invasive devices. Of 120 neurosurgical patients admitted to the ICU of the University Hospital of the West Indies (UHWI) between September 1995 and December 1999, the records of 73 patients were available for analysis. All had prophylactic antibiotics. Twenty-one of these 73 patients (28.8%) developed 22 infections after a mean of five days in the ICU: nine with chest infection, seven with urinary tract infection, four with central nervous system (CNS) infection and one each with wound and skin infection. This is an incidence of 11.6/1000 patient-days. The responsible organisms included Pseudomonas (7/21), Acinetobacter (3/21), E. coli 2/21, Enterobacter (2/21), and Klebsiella (2/21), and one each with Staphylococcus aureus, methicillin resistant Staphylococcus aureus, coagulase negative Staphylococcus, group D Streptococcus and bacteroides (1/21). Infection was significantly related to length of hospital stay, length of ICU stay, duration of intubation, duration of ventilation and the presence of diabetes mellitus. All patients who had surgery after ICU admission developed infection, seven with chest infection, two with urinary tract infection, two with CNS and one with skin infection. The three patients who were admitted with intracranial infections all developed other infections. Infected patients had a significantly longer hospital stay. Five patients died, none directly attributable to infection, while 55 (75.5%) made a good recovery. The problem of ICU infection may be expected to escalate with the increased use of intensive care, increasingly more complex surgical procedures and the growing problem of antibiotic resistance. Since infection is related to the length of ICU stay, earlier discharge of neurosurgical patients to an appropriately staffed high dependency unit is likely to result in reduction of the infection rate. Reinforcement of infection control strategies within the ICU may be expected to further minimize the infection rate.