The determination of phosphates by the classic quimociac gravimetric technique was used successfully as a laboratory experiment in our undergraduate analytical chemistry course. Phosphate-containing compounds are dissolved in acid and converted to soluble orthophosphate ion (PO[subscript 4][superscript 3-]). The soluble phosphate is easily precipitated as quinoline molybdophosphoric acid by the addition of a single reagent. The precipitate is easily filtered, dried, and weighed. The method has the advantages of producing a predictable, stable, high molar mass precipitate that students find easy to form, filter, dry, and weigh. This technique is well-known for its precision and accuracy. Students can also learn about the formation and structure of 12-heteropoly molybdophosphoric acid. (Contains 1 figure.)