Abstract. Hysterosalpingo-contrast sonography is an accurate first-line method used to test for tubal patency in human gynecology. Tubal pathology occurs in dairy cattle and is a reason for infertility, but easy and accurate methods to test for tubal patency are not available in the living cow. In this study it was thus investigated if contrast sonography (CS) using Echovist ® -200 as the echo-contrast medium is a feasible procedure to test for tubal patency in dairy cattle. In eight repeat breeder Holstein Frisian cows, all of them being in behavioral estrus, Echovist ® -200 was given into the uterus and its exit into the abdominal cavity then imaged by transrectal conventional B-mode ultrasound, and used as indicator for tubal patency. Animals were slaughtered one day later and the genital tracts subjected to gross morphology and histology in order to confirm the results of CS. In two cows, CS was prematurely terminated after examination of one oviduct because of rectal bleeding, while CS completely failed in another cow because of poor image quality. In five cows, both oviducts could be examined by CS, respectively. A total of five oviducts were found patent by CS and confirmed by post mortem examination. Two out of five oviducts diagnosed as occluded by CS were morphologically intact and thus misdiagnosed. Of the three non-patent oviducts, two were occluded because of a hydrosalpings, respectively, while the third was inflamed. In conclusion, CS has been shown a feasible procedure to test for tubal patency in dairy cattle. Further studies with more animals are however recommended to warrant this result. Repeat breeder cows are usually referred as to infertile animals that are bred several times but do not conceive and return to estrus in a regular interval, in the absence of signs that can be associated with not conceiving [4]. Repeat breeding is a multifactorial problem involving a multitude of extrinsic as well as intrinsic factors including subtle genital disorders [5][6][7]. Tubal pathology has been associated with infertility in dairy cattle [8][9][10], but its contribution to the repeat breeder syndrome has yet not been determined. This is due, at least in part, to the difficulty in the assessment of the oviducts in the living cow. Rectal palpation, laparotomy and laparoscopy have been advocated as viable methods for this purpose [11], however these are either inappropriate to test for tubal patency and/or unreliable, laborious and expensive. In contrast, tubal patency in cattle can be tested using the red dye phenolsulfonphtalein (PSP). When it is given into the uterus as a solution, it flows into the abdominal cavity in case of tubal patency, where it is resorbed and then excreted in urine [11,12]. Using the PSP test false positive results are however occurring [11], and testing of individual oviducts is impossible. In woman, where tubal dysfunction or obstruction accounts for approximately 35% of all the causes of infertility [13], hysterosalpingo-contrast sonography is a widely used first-line scre...