Two years of prospective data on 416 back injuries were gathered at a 1100-bed acute and tertiary care hospital to assist target prevention efforts. The rate of injury among 1645 nurses was found to be highest for those working on orthopaedic, medicine, neurology, spinal and surgery wards, indicating priorities for prevention. In fact, 51% of the orthopaedic nurses sustained at least one back injury during the two-year period. Gender did not significantly affect the risk of back injury; however, injuries were slightly more common in nurses with less seniority and younger nurses were found to be at significantly increased risk of back injury. Almost 63% of the back injuries which occurred in nurses working 8 h shifts on the high-risk wards occurred during the first two hours of the shift. Lifting and transferring patients with assistance were the two most common mechanisms for back injury (22.6% and 23.3%, respectively). In total, injured nurses attributed 52.3% of their injuries to inadequate training; inadequate staffing was given as the primary reason for 13.8% of the injuries. The results suggest that training in the indications for and use of mechanical devices for lifting/transferring patients requires intensification, and a 'warm-up' period should also be considered in the face of injuries occurring early in the shift if work activities cannot be evenly planned.