Technical Abstract: The Hypocreales, Beauveria bassiana, Metarhizium anisopliae sensu lato, Isaria fumosorosea and I. farinosus, and Nomuraea rileyi, have become important insect control agents in recent times and consequently subjects of much scientific study and development. Mass production of infective stages is important for obtaining sufficient quantities of infective stages for field studies of these fungi. Conidial production on agar media in Petri dishes is generally insufficient for such purposes. There are several methods for mass production, involving solid substrate fermentation for aerial conidia, and liquid fermentation for blastospores or microcycle conidia, and for a novel structure, evidently specific to Metarhizium spp., the microsclerotium. This chapter presents basic techniques for all these procedures, techniques that should allow any laboratory to produce hypocrealean fungi for their use, as well as provide a theoretical basis to adapt mass production to local requirements and devise technical improvements.