The use of various compounds in gamma encephalography with the scintillation camera is presented. A method of preparation of technetium 99m/iron/ascorbic acid complex is described. Advantages and disadvantages in the clinical use of the complex are discussed. In our hands, technetium 99m/iron/ascorbic acid complex has proved to be the agent of choice for both the scintillation camera and the rectilinear scanner in the detection of brain lesions.