This Bureau of Mines study illustrates the economic significance of the Florida phosphate industry to the state and to the nation. Environmental considerations related to phosphate industry activity are discussed briefly. Based on forecasts of Florida phosphate production in 1975 and using 1972 dollars, regional and national output value, income, and employment created by the phosphate industry were estimated for 1975. State and federal government tax revenues generated by the phosphate industry are also measured. Further, the concentrated impact of the phosphate industry on certain Florida areas and on regional industries is examined. Finally, the phosphate industry's importance to the U.S. balance of payments, U.S. agricultural production, and the frasch sulfur industry is considered in addition to byproduct fluorine and potential byproduct uranium from fertilizer manufacturing.