The aim of this B. Sc. Thesis was to study and to analyse the influences of conformation traits on longevity and milk production of dairy and dual-purpose cattle breeds. According to different studies, udder traits, stature and feet & leg traits have an important influence on milk yield and longevity of dairy cows. Cows with strong fore udder attachment, correct feet and proper legs usually have higher milk production and better longevity. The size of the stature of the animal is positively related to the milk yield, but on the other hand it has a negative influence on longevity of the animal. The same is considered for the angularity. Slovenian cows, which have given over 100,000 kg of milk in their life, were studied. Until 2016, 129 cows have reached this goal. 96 of them were Holsteins, 18 Brown Swiss, 4 Simmental breed and there were also 11 crossbreed cows, that have yield over 100,000 kg of milk in their life time. Simmental breed cows have reached the highest average lifetime milk, fat and protein production among aforementioned cows. In comparison with the rest of their peers, the analysed group of 129 high-productive cows has achieved better scores for the udder traits, feet & legs traits and stature, when assessed in their first lactation. The same findings have also been established in other similar studies. Proper feet and pasterns, excellent fore udder attachment, strong central ligament, appropriate udder depth, and very high and wide rear udder have the greatest influence on longevity and lifetime milk yield among all type traits.