Early pregnancy diagnosis significantly affects the efficiency of the intensive swine production. Furthermore, early pregnancy diagnosis of non-pregnant animals reduces the number of non-productive feeding days per sow, considerably increases the utilisation efficiency of housing space, and enables timely interventions during medical examinations of each animal. Traditional methods of pregnancy diagnosis, such as the detection of the lack of oestrous cycle in inseminated animals, the determination of progesterone and oestrone sulphate in blood and/or urine, the examination of vaginal and cervical discharge, and the rectal palpation of reproductive system, are either imprecise or impractical regarding production conditions. Ultrasound diagnosis is a sophisticated method of highly precise early pregnancy diagnosis deprived of negative effects on examined animals. Moreover, this method provides a real-time visualisation of conceptus, uterus, and ovaries. Ultrasound diagnosis enables pregnancy diagnosis as soon as 17 days after insemination. Well over 95% of accurate diagnoses are obtained during examinations conducted between 25 and 35 days after insemination. The only disadvantage of this method, which notably impedes mass application in production, is a fairly steep price of ultrasound equipment.