The study of parasitic species associated with economically valuable coral reef fishes is an important area of research that contributes to successful and sustainable management of fisheries and aquaculture systems throughout the world. Whether wild-caught or reared in captivity,harvested species inevitably become affected by associated environmental stressors that in turn raise the impacts of pathogenic parasites . Therefore, knowledge about fish parasites is essential for successful rearing of coral reef fishes in aquarium. For this reason, we aimed to investigate the prevailing parasitic diseases of coral reef fishes in Aquarium in Hurghada, Red Sea province under captivity seasonally. These aims will be achieved through: 1. Clinical and postmortem lesions of some aquarium coral reef fishes in Hurghada, Red Sea. 2. Isolation &identification of the most common external &internal parasites affecting such marine fishes. 3. Investigation on the prevalence of isolated parasites. 4.Recording the pathological alterations produced by such parasites.