The principles of 'lean management' have permeated many sectors of today's business world, secondary to the success of the Toyota Production System. This management method enables workers to eliminate mistakes, reduce delays, lower costs, and improve the overall quality of the product or service they deliver. These lean management principles can be applied to health care. Their implementation within the ambulatory care setting is predicated on the continuous identification and elimination of waste within the process. The key concepts of flow time, inventory and throughput are utilized to improve the flow of patients through the clinic, and to identify points that slow this process -- so-called bottlenecks. Nonessential activities are shifted away from bottlenecks (i.e. the physician), and extra work capacity is generated from existing resources, rather than being added. The additional work capacity facilitates a more efficient response to variability, which in turn results in cost savings, more time for the physician to interact with patients, and faster completion of patient visits. Finally, application of the lean management principle of 'just-in-time' management can eliminate excess clinic inventory, better synchronize office supply with patient demand, and reduce costs.