Two hundred specimens of the cyprinid fish Puntius binotarus were collected over a period of 1 year, February 1976January 1977, from an irrigation canal in Palau Pinang, Malaysia. Six species of parasites were recovered: Dactylogyrus sp., Rhabdochona penengensis Furtado, 1965; Proreocephalus sp., Bothriocephalus acheilognathi Yamaguti, 1934, Pallisenfis gaboes MacCallum, 1918 and Lumproglena minufa Capart, 1943. The prevalence and mean density of two ectoparasites (Dactylogyrus sp. and L. minufa) and an endoparasite (B. acheilognathi] were examined in relation to season and host size. Fish were found to be free of these parasites in many months of the year. Prevalence and mean density of Dacfylogyrus sp. and L. minufa were found to be highest during the early part of wet season, whereas those of B. acheilognafhi were found to be highest in the later part of wet season. Prevalence of L. minufa increased with increasing size of fish, but mean density was least in the largest fish. Both prevalence and mean density of B. acheilognafhi were highest in smaller fish, whereas that of Dacfylogyrus sp. showed little variation in the three size-groups.