Direct heat use of geothermal energy in the United States is recognized as one of the alternative energy resources that has proven itself technically and economically, and is commercially available. Developments include space conditioning of buildings, district heating, groundwater -heat pumps, greenhouse heating, industrial processing, aquaculture, and swimming pool heating. Forty four states have experienced significant geothermal direct use development in the last ten years. The total installed capacity is 5.8 million Btu/hr (1,700 MWt), with an annual energy use of over 18,000 billion Btu/yr (4.5 million barrels of oil energy equivalent). In this article we provide an overview of how and where geothermal energy is used, the extent of that use, the economics and growth trends. The data is based on an extensive site data gathering effort by the Geo-Heat Center in the spring of 1988, under contract to the U.S. Department of Energy