This investigation was designed to determine if sulfate metabolism is the function of a particular cell organelle, or whether the site of sulfation varies, depending upon the type of cell and the class of sulfated compound. Rats and mice were injected intravenously with inorganic sulfate labeled with 35S (H235SO4), and were then killed by vascular perfusion of fixative 5–30 min later. Several tissues were prepared for electron microscope autoradiography. 14 different types of specialized cells which incorporated the labeled sulfate were analyzed. In every case, the sulfate was initially detected in the smooth membranes and vesicles of the Golgi complex. Available evidence indicates that these cells were engaged in the synthesis of several different sulfated compounds, including mucopolysaccharides, glycoproteins, lipids, and steroids. These results lead to the generalization that the enzymes required for the transfer of inorganic sulfate to a variety of acceptor molecules are located in the Golgi complex.