Milligram quantities of fluoride may be determined by a rapid, convenient method using a turbidimetric titration. The simple apparatus is easily and quickly assembled from materials that are generally available. It permits the use of cells varying in size from glass tubing 1 cm in diameter to large beakers, depending upon the volume of solution and type of precipitate obtained. With calcium ion as the titrant, concentrations of 0.01 to 0.09M fluoride ion may be determined with an average relative error of plus or minus 2%. Thorium ion may be used as the titrant to deterine fluoride ion from 0.04 to 1.0M, with an average relative error of plus or minus 2%. As little as 0.4 mg of fluoride ion in 2 ml of solution may be determined with a relative error of plus or minus 4%. The time for a single determination is generally less than 10 minutes. (auth)