Safety analyses of drilling operations are often written from the perspectives of regulation, economics, industry structure, etc. The ergonomic perspective on safety emphasizes that equipment and operations should be designed in light of human capabilities and limitations. To demonstrate this approach a scenario analysis was performed on records for 134 safety incidents on oilwell drilling rigs. The characteristics of the most critical scenarios were then considered to determine the extent to which the ergonomics of environment, equipment, and work methods might have contributed. Ergonomic data was collected at four drilling sites, including a prototype semi-automated rig. From both ergonomic and safety perspectives, the work situation of operators on a conventional rig floor is most in need of remediation. Mechanical pipe handling would provide the most complete solution to this unpleasant and unsafe environment, its strenuous and over-extending tasks, and the risks inherent in putting people near heavy moving objects. Significant improvements can be made at the detail level and at minimum cost in some tasks. Improvement in other tasks requires basic conceptual changes in rig systems and architecture. To realize their potential, new rig concepts must be carefully and systematically designed, and ergonomics should be considered throughout their design.