The aim of this study was to invastigate the effects of seasonal variations on the metabolic parameters in cattle. Thirteen Swiss Brown cows aged 3 – 4 years were used in the study. Plasma samples were collected four times a year at each seasons; August (D1), November (D2), February (D3) and May (D4). Concentrations of metabolic parameters was determined via autoanalyzer (Olympus AU 600, Optical Co Ltd., Japan). Seasonal variations were observed in total protein, albumine, globuline, glucose, BUN, Ca, P and Mg levels. This study indicates that seasonal differences in the some metabolic parameters are significant and this should be considered when these parameters is commented.