Fish is consumed as a rich and cheaper source of white meat and proteins all over the world. Fish farming is the leading source of income generation throughout the world. The present research study was conducted with aims to investigate the ecto and endo parasitic fauna of Schizothorax plagiostomus (Snow Trout) in River Swat. A total of 96 fish samples were collected on monthly basis from July-2018 to February-2019, from upper, middle and lower reaches. Fish samples were collected with the help of cast net, hand net and fishing rods. Local fishermen and experts help were also sought out for fish collection. 61 out of 96 were found infected by helminth parasites. The total prevalence and intensity of 63.54% (61/96) and 2.90 (177/61) was collected respectively during data analysis. The P value less than 0.05% at 95% CI was considered significant. Highest monthly prevalence of 83.33% was recorded during July and August, while lowest prevalence of 33.33% was noted during February. Five species of helminths parasites were detected from S. plagiostomus, of which two were trematodes (R. shizothoracis and Rhabdochona species), one species of Monogenia (D. paraddoxum), one species of Cestodes (Nippotaenia species), and one species of Acanthocephalan (N. devdevi). Highest parasite wise prevalence and intensity of 21.87% and 4.09 was noted for R. Schizothoracis, while the lowest prevalence and intensity of 4.16% and 1.25 was noted for Nippotaenia species. Highest relative density of helminth parasites were observed in the month of July while the lowest relative density was observed in the month of January. Highest infection of 76.08% was observed in adults host while 40% infestation rate was observed in young fish samples. According to sex wise data analysis, 73.68% prevalence was observed in female hosts while only 56.90% prevalence was observed in male individuals. Higher infection (83.33%) was noticed during summer season, while lowest infection (44.44%) was observed during winter season. Similarly large numbers of fishes (71.79%) were found infected that were collected from lower reaches of the River Swat than the fish samples collected from upper reaches (52%).