Defining urban sprawl is a difficult task. Beyond low-density, uncontrolled development and urban expansion, there is no one unified concept or definition. As a consequence, several metrics and indicators are used to characterize urban sprawl. A literature review has been done in the first part of this thesis in order to complete the difficult task of finding the ideal set of indicators and thereby an ideal definition, that may also be applied to our case study of the San Juan Metropolitan Area. One of the main concerns of this thesis is the environmental consequences of urban sprawl. Therefore, further on in the literature review, a discussion of the causes and consequences of sprawl will show how the automobile plays a very important role in both being the origin of the 'problem' and in its increased use resulting in more carbon dioxide emissions and concentrations. The change and loss of landscape is the other important environmental consequence of sprawl. The second part of this thesis draws its focus to the San Juan Metropolitan Area in Puerto Rico (SJMA). Representing the main urban areas of the island, the San Juan Metropolitan Area has gone through an interesting process of development and urban growth. Following in the United States' footsteps, Puerto Rico experienced rapid growth in population and in infrastructure development during the 1950s. With a steady population growth rate until the late 1990s to early 2000s and an ever increasing use of the car as a means of transport, suburbanization was practically inevitable. More recent years show for a slow-down in population growth, but the consequences and outcomes - traffic congestion and loss of landscape, for instance - of sprawl remain. To fulfill the ultimate aim of this research - finding appropriate policy approaches to mitigate and control the negative effects of sprawl in the SJMA - census data, income data, transport data, land use regulation data, and remote sensing image information have been used and analyzed to list the policy implications accordingly. In order to make urban life more attractive than suburban life in the SJMA, more investments are required in the public transportation system and in the betterment of the other public amenities the urban centers of the SJMA have to offer. An island-wide land use regulation system is also required.