The use of biological control for the management of insect pests is gaining importance day by day as a safe and sustainable alternative for harmful chemical pesticides. In this context, the role of parasitoids, predators and microbial bio-pesticides in bio-intensive pest management became important. This chapter discusses in detail about an egg, larval, pupal, nymphal, adult and intermediary parasitoids and predators belonging to different orders that are useful in biological control. The bio-pesticides used to control insect pests: Bacterial and viral pathogens, entomopathogenic fungi and entomopathogenic nematodes were discussed with examples for their commercial exploitation. This will give a way forward to plan a holistic approach to restore damaged agriculture ecosystems and develop a dependable package of practices for pest management to organic farming systems.