Ultrasound techniques are becoming increasingly important in animal reproduction, offering both a mean of diagnosis and a useful therapeutic tool. Accordingly, understanding the use of ultrasound technology is critical in contemporary animal sciences, since ultrasound examinations are now a routine component of diagnostic workups in reproduction. Ultrasound technology offers the assessment of pregnancy status and foetal viability early post breeding in order to identify animals that fail to conceive, improving reproductive efficiency; early identification of animals carrying twin foetuses, allowing for the implementation of differential management strategies to avoid the negative effects of twinning on general health of the mother animal and also at parturition; and the visualisation of ovarian and uterine pathologies not accurately detected via rectal palpation, allowing appropriate therapies to be implemented. In addition, determination of foetal sex in utero can be done by ultrasonography. The new information that has been generated through ultrasound has thrown light on therapeutic uses, thereby opening up new areas for research. Moreover, ultrasound-guided interventional techniques can be used for diagnostic or therapeutic purposes. In this review, advances and applications of ultrasonography in domestic animal reproduction are reviewed.