The introduction of transmissible parasites through the import of ornamental fishes may cause serious disease problems in native fish species. This may have negative impact on emerging ornamental fish trade in Pakistan. The biodiversity of the Pakistan must be protected by taking some serious steps on the control of the imported diseased ornamental fishes. Ornamental fish have been produced in other nations for over 100 years but are still not introduced in Pakistan and therefore, Pakistan does not have its own aquaculture industry and are dependent on the imported ornamental fishes to meet the demand of the customers and hobbyist. The introduction of transmissible parasites through the import of ornamental fishes may cause serious disease, problems in native fish species. This may have negative impact on emerging ornamental fish trade in Pakistan. The biodiversity of the Pakistan must be protected by taking some serious steps on the control of the imported diseased ornamental fishes. The aim of the study is to investigate the parasitic fauna that increased fish mortality rate and find the Prevalence and Mean Intensity and Abundance of parasitic infestation on different fish organs. Sampling and collection was done. Samples of fishes were carried in areated clean polyethylene bag in the Fish Health Management Laboratory, Zoology Department, University of Punjab, Lahore. After transporting to lab, fishes were kept in the glass aquarium facilitated with contrlled temperature. Then the Morphological and physical Observations were done. Analysis of morphometric characteristics was done according to methods propsal by Roberts (1989), Kabata (1985), Bauer et al., (1973), Noga (2010). Last step was the analysis of parasitic infestation of fins, mouth and gills and observed under microscope. Photographts of the parasites were taken. The results showed that the percentage of Gyrodactylus sp., Centrocestus sp. and encyst metacercaria was 7.50%, 5% and 30% respectively. Encyst metacercaria Centrocestus sp. showed highest parasitic infestation. Keywords: Parasitic disease, Ornamental fish, (Rainbow Shark, Dactylogyrus sp. Centrocestus sp).