Carsharing (or short-term auto use) provides a flexible alternative that meets diverse transportation needs across the globe while reducing the negative impacts of private vehicle ownership. Although carsharing appeared in Europe between the 1940s and 1980s, the concept did not become popularized until the early 1990s. For nearly 20 years, worldwide participation in carsharing has been growing. Today, carsharing operates in approximately 600 cities around the world, in 18 nations and on 4 continents. Approximately 348,000 individuals share nearly 11,700 vehicles as part of organized carsharing services (>60% in Europe). Malaysia is operating a carsharing pilot, with a planned launch in 2007. Another eight countries are exploring carsharing. Thirty-three carsharing expert surveys were identified on an international basis. Cost savings, convenient locations, and guaranteed parking were identified as the most common motivations for carsharing use worldwide. An international comparison of carsharing operations, including similarities and differences, is provided. Continued growth is forecast, particularly among new and emerging market segments, such as businesses and universities. Growth-oriented operators will continue to account for the largest number of members and fleets deployed worldwide. In addition, high energy costs; limited and expensive parking; ongoing diffusion of operational knowledge, benefits, and supportive technologies; and increased demand for personal vehicle access in developing nations will affect carsharing’s growth and expansion.