We reviewed all patient safety incidents reported to the UK National Patient Safety Agency between August 2006 and February 2007 from intensive care or high dependency units. Incidents involving equipment were then categorised. A total of 12 084 incidents were submitted from 151 organisations (median (range) 40 (1-634) per organisation). Of these, 1021 incidents were associated with use of equipment, most commonly involving syringe pumps/infusion devices (185 incidents), ventilators (164 incidents), haemofilters (107 incidents) and monitoring equipment (70 incidents). Twenty-nine incidents were associated with more than temporary harm to patients. Failure or faulty equipment was described in 537 incidents (26% with some harm) and incorrect setting or use was described in 358 incidents; these were more likely to be associated with harm (39%; p = 0.001). We suggest changes to improve the reporting of incidents and to improve equipment safety.