In this study, the gastrointestinal organs of the 50 cattle were examined for the gastointestinal nematodes and their seasonal activities, between September 1992 - August 1994, in Kars district, in Turkey. All the examined animals were infected with the gastrointestinal nematodes. In cattle 20 nematode species were determined. The 120222 nematodes were collected from infected cattle. The total number of parasites for each animals were ranged between 33-16152 in cattle. The average number of parasites in cattle were determined as 2404.4. The number of nematode species of each animals were ranged between 1-8 (mean 3.46). Dominant species in infected cattle were determined as follows : Ostertagia ostertagi (92 %), Trichostrongylus axel (58 %), Cooperia oncophora (48 %), C. pectinata (24 %), C. mcmasteri (14 %), Oesophagostomum venulosum (22 %), Marshallagia marshalli (14 %) and Trichuris discolor (14 %). Ostergia, Cooperia and Trichostrongylus species in cattle were determined in all seasons of two years, but the highest infection levels were noted in Trichostrongylus spp. in winter, Cooperia spp. in summer and autumn, Ostertagia spp. in summer, autumn and winter.