The objective of this study was to compare Iranian Holstein (HO) and Brown Swiss (BS) cows, for milk, fat, and protein yields, somatic cell score (SCS), fat corrected milk (FCM), days open (DO) and calving ease. The dataset included 9700 Holstein dairy cows from 38 herds and 2500 Brown Swiss cows from 13 herds from the years 2011 to 2017 through first to third lactation. The dataset was recorded from the herds in southeast of Iran by the National Animal Breeding Center and Production of Animal Products. The SQL 2016 software was used to edit the dataset. The SAS software version 9.4 with Proc MIXED were used for productive traits and days open and the Proc GLMMIXED were used for calving ease. Finally, a model including breed, Herd-Year-Season of calving, parity and breed within parity as fixed effects and cow and error term as random effects for milk, fat yiled, protein yield, Fat Corrected Milk (FCM), Somatic cell Score (SCS) and DO were used. Also for calving ease a model including breed, sex of calve, weight of calve and lactation number as a fixed effects and cow and error term as random effect were used. The results of current study represent that Holstein cows produced 2033 ,1028 and 996 (kg) milk more than Brown Swiss cows during the first to third lactations respectively (p 0.0001). Moreover, FCM estimated for both breed and the result indicated that Holstein cows had 0.53, 0.88 and 1.2 daily milk more than that in the Brown Swiss cows respectively (p 0.0001). For fat yield, Holstein cows had significantly difference vs. brown Swiss cows and they had 31.75, 39.65 and 44.96 kg more fat than Brown Swiss cows during the first to third lactations respectively (p 0.0001). For protein yield also, Holstein cows had significantly difference vs. Brown Swiss cows and they produced 30.63, 27.94 and 27.92 kg more protein than Brown Swiss cows during the first to third lactations respectively. The Holstein cows showed more sensitivity to mastitis than Brawn Swiss. The SCS for Holstein cows were 0.70, 0.76 and 0.43 unit more than Brown Swiss cows during the first to third lactations respectively, which indicated that may be the the genetic background for mastitisn resistance of this breed is more stonger that that in Holstein cows (p 0.0001). The calving difficulty incidence for Holstein cows was higher than it in Brown Swiss cows in the first and second lactation. The Brown Swiss cows had 1.1 and 2.5 percent calving difficulty less than Holstein cows in the first and second lactation (p 0.0001). However in the third lactation, they showed 0.3 percent calving difficulty more than it in Holstein cows (p 0.03). The least square means of days open was significantly differed for Holstein cows. The Holstein cows had 8.00, 10.82 and 5.56 days, more DO than it in Brown Swiss cows (p 0.0001).The results of this study can help farmer to consider the abilities of other dairy cattle except Holstein to choose the best dairy breed according to their climate region, the target market and their reproductive problems. Keywords: Dairy Cows, Holstein Cows, Brown Swiss cows, Productive traits, Reproductive traits