Morphological evaluation of sperm has a long history and is an essential element analysis of semen, which provides breeders invaluable information to assess the health status of animal and its potential fertility. An important role is played by the percentage of healthy sperm due to abnormally developed. This value plays an important role in the usability of quality in breeding stallions. Stallion sperm intended for artificial insemination breeding mares in native form may not contain more than 40 % of defective sperm and the total amount of their activity should not be below 60 %. In the case of benefits intended for deep freezing is allowed only 20 % pathological forms of sperm. Activity selected for cryopreservation of semen should not fall below 80 %. The topic of the thesis was to determine the frequency of morphologic sperm defects in a group of stallions stud farm Tlumačov s.p., included in breeding season for 2013. Sperm morphology examination was performed on 72 samples of ejaculates collected from 12 stallions during the breeding season from May to August. For each stallion sperm activity was recorded of subjective method, immediately after collection, and the correlation was observed with respect to morphological abnormalities of the same sample. To investigate the morphological structure of sperm abnormalities were stained with two methods of cytological stain -- staining of B.T.Farelly and staining of Čeřovský. After staining the preparations were evaluated under a light microscope. Identified defects were divided into 6 categories - defects in the head, acrosome defects, defects of the neck, tail defects, abnormal forms of sperm and immature sperm. We studied a number of normospermia and total sperm pathology also expressed as a percentage. Another part of the analysis was a theoretical comparison of both the staining techniques with respect to suitability for the examination of morphological sperm abnormalities in stallions.