Achromobacter xylosoxidans, a Pseudomonas-like bacterium, contaminated a boar stud laboratory’s water distillation and delivery system that was used for extension of raw semen for artificial insemination. In sow herds that used the contaminated semen, conception rates decreased and vulvar discharges, culled sows, and nonproductive sow days increased. Thorough diagnostic testing revealed that A xylosoxidans was the etiological agent of endometritis and subsequent reproductive failure in these sows and gilts. This is the first known report of female reproductive failure attributed to A xylosoxidans. Routine cleaning and control measures to reduce bacterial growth in the extender ultimately failed to eliminate A xylosoxidans. Following short-term elimination of A xylosoxidans from the extended semen, reproductive parameters in the sow herds returned to their previous levels.