Red snapper Lutjanus argentimaculatus (Forsk., 1775) is infected by the trematodes, cestodes, acanthocephala, nematode larvae and adults which cause damage to the intestine, stomach, liver, visceral mesenteries, kidney and spleen of the fish. Infection rate of nematode larvae found to be very heavy and produces destruction of all layers of stomach and intestine along with fibrosis of visral wall. Acanthocephala may also badly affect the gastric mucosa and granulomatous lesions are produced at the site of penetration and perforation was also produced with large granulomas on serous surface. Trematodes produce dissolution of the epithelial cell of villi which appeared as granular masses. Neoplastic growth in intestine and loss of upright morphology of all layers occurs. Liver appeared abnormal and lesions were present in the superficial tissue caused by nematode and acanthocephala. This information is an important addition to the scientific literature and useful for parasitologists and fish pathologists.