The formation of meat mutagens has been studied the last 10 years by carrying out modeling and meat cooking experiments in parallel. During this time, the list of meat mutagens has been growing, and continues to grow. The meat mutagens are usually produced in the crust of animal foods during frying, broiling, and baking. Another important source is meat extracts, consumed as gravies and meat bouillons. The formation of meat mutagens has been shown to depend physically on time, temperature, and water. Three major precursors have been identified: creatine or creatinine, certain amino acids, and monosaccharides or disaccharides. A requirement of sugar assumes a participation of the Maillard reaction, which also forms the basis for one of the major reaction mechanisms suggested. However, the meat mutagens are produced also in the absence of sugars, which means that other routes might be possible as well. Although the major precursors have been identified, more work needs to be done on the reaction mechanisms, the kinetics, and on the food constituents that might enhance or inhibit the formation of the meat mutagens. The results obtained to date point to several possibilities to control the formation of meat mutagens.