An intervention study of cashiers at a large grocery store was begun in response to employee symptoms of musculoskeletal discomfort, primarily shoulder, neck, and upper back pain, after introduction of a new express checkstand. The grocery company then instituted workplace changes directed at reducing stressful postures and the discomfort in the anatomical sites of primary concern. These changes were placement of a physical barrier to reduce trunk flexion from overreaching, installation of an adjustable keyboard to reduce static shoulder stress, and education of employees about good workplace practices to reduce musculoskeletal stress and fatigue. There was a statistically significant reduction in neck, upper back, or shoulder discomfort but not arm, forearm, or wrist discomfort. There was also a significant reduction in employee use of medication and days to recovery from discomfort but not in overall number of employees with symptoms or in hours able to operate the checkstand without discomfort. We found that ergonomic interventions, directed to the anatomical site of greatest employee concern, are likely to be effective, that employees were a good source of information on the ergonomic problems and solutions in their workplace, but that the overall approach must be iterative to achieve the maximum effect.