AbstractThis chapter presents various technologies for the in vivo (culture of entomophilic nematodes in insect hosts) and in vitro (Dauer juvenile and recovery, solid-phase production, liquid culture, and liquid culture process technology) production of entomophilic nematodes, and describes the developmental biology of entomophilic nematodes in liquid media. Research on Steinernema and Heterorhabditis spp. is largely covered.