In the 1940s, when the governor of Puerto Rico was still appointed by the U.S. president, a large state-owned enterprise (SOE) sector was established. Later, in 1948Later, in -1950, the island's first elected government privatised these SOEs. This paper documents both the creation of the SOE sector and its privatisation, and analyses the role played by ideology, political interests and economic concerns in the decision to privatise. Whereas ideological factors might have played a significant role in the building of the SOE sector, the privatisation process was driven by economic factors. In the cement sector, the competing private firm was more efficient and the SOEs in other sectors with no private competitors in the island showed permanent losses.