Hydrocarbon feedstocks are hydroprocessed in reaction systems including at least one catalyst stage containing bulk metallic catalysts comprised of a Group VIII metal, a Group VIB metal, and an organic compound-based component. The catalysts are prepared by a method wherein precursors of both metals are mixed and interacted with at least one organic acid, such as glyoxylic acid, dried, heated, and sulfided. The catalysts are used for hydroprocessing, particularly hydrodesulfurizaton and hydrodenitrogenation, of hydrocarbon feedstocks.