This study was conducted to assess the effects of stage of lactation, parity and sampling season on milk yield and milk components in Jersey cows in Karakoy State Farm, Turkey. The data set consisted of 2657 milk records of 204 Jersey cows collected from September 2011 to December 2013. For this purpose, test day milk yield (TDMY) records and milk samples were taken once a month for 10-month period after parturition. The effect of stage of lactation, parity and sampling season on TDMY, fat percentage, protein percentage, fat yield and protein yield were found statistically significant (P<0.01). TDMY were correlated with fat percentage (-0.235) and protein percentage negatively (-0.254) but with fat yield (0.755) and protein yield positively (0.950) (P<0.01).