Aim of study: Microorganisms infecting insects are known as entomopathogen. This group includes viruses, bacteria, protists, fungi and nematodes. They are found in nature and commonly isolated from soil and host insects. They cause desirable (in plant pests and parasitic insects) and undesirable infections (in useful insects such as silkworms, bees, predators) in insects. In this paper we aim to document entomopathogenic organisms that have been recorded from Kastamonu region.