In the graduation thesis we analysed milk production, fertility and longevity of dairy cows on organic dairy farm Bogata in Bovec for the period of nine years (2010-2018). In this period the number of dairy cows on the farm varied between 76 and 106, the average milk yield in the standard lactation period varied from 5,463 kg in 2014 and 6,757 kg in 2010. The average total milk production in the analysed period was 518,047 kg per year, with the average fat content of 3.57 % and protein content of 3.15 %. Replacement rate varied between 8.3 % in 2010 and 25.9 % in 2017. The period between calving and the next conception date was at its shortest in 2017 with 120 days and the longest in 2014 with 206 days, while the average period between the calving’s was between 400 days in 2017 and 489 days in 2014. In the analysed period there was 163 cows culled from the farm due to the three most common reasons - diseases and damage of hooves and legs, reproduction disorders and age. The cows were culled at the average age of 2,913 days and their average life milk yield was 33,942 kg of milk. In this period the culled cows produced in average 17.6 kg of milk per milking day, 15.58 kg of milk per feeding day and 9.97 kg of milk per life day. The survival of cows was reducing intensively with each year after the first calving. Only 20 % of cows that calved for the first time in 2010 reached the age of 8 years.