As has been widely documented, Argentina is in the process of dramatic change from a centrally controlled economy with protected markets to a competitive economy with open markets. The pace of change and its evident success testifies to the leadership of President Carlos Menem, who took power in July 1989. A central pillar of the change process is the privatisation of state companies, of which YPF – the Argentine national oil company – has been the most dramatic example. In just two years, YPF transformed itself from a lumbering behemoth of 39,000 people with widely diversified activities, protected from competition, into a lean, efficient, highly competitive oil company whose initial stock offering was widely hailed as marking one of the most successful privatisation efforts of our time. YPF's story offers useful lessons not only for companies undertaking privatisation, but for all organisations striving to change.