Background <p>Krukenberg tumors are a rare condition representing only 1% of ovarian tumors. Lynch syndrome only results in ovarian tumors in 1% of cases. Both diagnoses can be challenging, leading to delayed treatment. In this case report, we present for the first time the association between both Krukenberg tumor and Lynch syndrome, showing the difficulties the team encountered making this diagnosis.</p> Case presentation <p>A 35-year-old French Caucasian female patient presented with symptoms of bowel obstruction. Imaging studies were not very helpful in determining the origin of the tumor, suggesting possible infectious, neoplastic, or endometriosis-related causes. Surgery, although complicated, allowed for histological sampling, which revealed microsatellite instability. Given the rarity of direct ovarian involvement in Lynch syndrome, another origin was investigated, leading to the identification of a primary digestive tumor, called a Krukenberg tumor.</p> Conclusion <p>A thorough literature review on PubMed did not reveal any other cases of a patient presenting simultaneously with both Krukenberg tumor and Lynch syndrome. This case report could help other clinicians finding the right diagnostic in a shorter period of time and permit faster treatment improving patients’ outcomes.</p>