Introduction. The World Health Organization (WHO) points out that more than a third of the world's population is infected by one or more parasites. Ascariasis is the most prevalent parasitic disease in the world, with approximately 664 million people infested. Clinical case. A 22-year-old female patient enters the emergency department with general malaise, with worsening symptoms in recent days, intense abdominal pain, associated with nausea and uncontrollable vomiting. She also reports non-elimination of gas and absence of bowel movements. . An emergency ultrasound is requested, it reports the stomach with the presence of a linear, tubular echogenic image that moves in different directions. Discussion. The widespread use of ultrasound in Emergency Departments for the diagnosis of acute abdomen, as well as in the laboratory, allowed us to reach the presumptive diagnosis of temporary biliary obstruction due to A. lumbricoides, in addition, the presence of jaundice, direct hyperbilirubinemia and discrete elevation gamma-glutamyltransferase (GGT); findings that could direct the exploration of the bile duct during the surgical procedure. Conclusions. The importance of the clinical case lies in the use of abdominal ultrasound as a diagnostic method for Ascaris Lumbricoides. The use of ultrasound in emergency services is essential in the presence of an acute abdomen, and in any patient who presents acute biliary symptoms, always think about this pathology