Candidaemia is frequently a life-threatening complication in patients admitted to the intensive care unit (ICU). To assess the risk factors for candidaemia in critically ill patients with prolonged ICU stay, a total of 1765 adult patients admitted for at least 7 days to 73 medical-surgical ICUs of 70 tertiary care hospitals in Spain participated in a prospective cohort study. Candidaemia was defined as recovery of Candida spp. from blood culture. Sixty-eight episodes of candidaemia occurred in 63 patients, representing 35.7 episodes per 1000 ICU patients admitted, with an incidence rate of 1.5 episodes per 1000 days of ICU stay. Causative fungi were C. albicans in 57.1% of cases and non-albicans Candida spp. in 42.9%. In the multivariate analysis, independent factors significantly associated with candidaemia were Candida colonisation (OR = 4.12, 95% CI: 1.82-9.33), total parenteral nutrition (OR = 3.89, 95% CI: 1.73-8.78), elective surgery (OR = 2.75, 95% CI: 1.17-6.45) and haemofiltration procedures (OR = 1.96, 95% CI: 1.06-3.62). In the ICU setting in Spain and in patients who have stayed in units for >7 days, more than half of cases of candidaemia were caused by C. albicans. Risk factors for candidaemia identified included Candida colonisation, elective surgery, total parenteral nutrition and haemodialysis.