Background: The ornamental fish guppy (Poeciliareticulata) is a small colorful tropical cyprinid teleost fish. Lernaeacyprinacea (Anchor worm) are worldwide, crustacean copepod parasites that cause disease and mortality in several fish species of cultured or natural populations, especially wild-caught and pond-raised species of Poecilia. This study may be considered as a novel report from Kingdom of Saudi Arabia (KSA). Objective: The present study is an investigation of Lernaea isolates infecting apparently healthy Poecilia reticulate from KSA. Material and Methods: Guppy fish (Poeciliareticulata) were purchased two weeks prior to experiments. They were examined for parasitic infection and allowed to breed in the laboratory. They were observed for 15 days for appearance of infection by Lernaea spp. larva and adult parasites. The copepod specimens were removed by forceps, from different parts of the infected fish. Specimens were fixed in 70% alcohol, cleared in 90% lactic acid, mounted,and microscopically examined to identify the morphological features of L cyprinacea. Results: After 15 days L cyprinacea were detected in the ventral, anal and caudal fins of several P. reticulata. Intense focal inflammation and hemorrhage was easily observed at the attachment site, which appeared red and ulcerated. Total prevalence of infection was 68.1%. The prevalence of infection in females (79.3%) was greater than in males (33.3%). Conclusion: P.reticulatamay beconsidered as a newly recorded host of L. cyprinaceafrom KSA