The zebrafish is the most commonly used laboratory fish due to its prominence in biomedical research in regards to vertebrate development and disease, organ function, behavior, toxicology, cancer and drug discovery. Biosecurity risks and disease potential of laboratory zebrafish are highly influenced by their source and method of transport. This lecture will focus on the most common bacterial, parasitic and non-infectious diseases of zebrafish and treatment options available to the practicing laboratory fish veterinarian.