Annular pancreas is a rare embryonal abnormality. Its manifestation in adulthood is often pinpointed with a substantial delay, which is most often attributed to pancreatitis, biliary pathology or dyspepsia. We present a case of a 28-year-old woman who had exacerbating symptoms of high bowel obstruction from 20th week of pregnancy, progressing after premature delivery. Diagnostic work-up revealed partial annular pancreas compressing the duodenum. Despite attempts of conservative treatment, her state deteriorated to such an extent that surgery was indicated and gastrojejunal bypass created. Her postoperative recovery was uneventful. In cases in which symptoms of high bowel obstruction in pregnancy persist and prostration occurs, we suggest close monitoring and a more thorough diagnostic approach. The question remains whether annular pancreas presents a cause of pathologic findings, a cofactor, or a mere accidental diagnosis in the development of superposed pathologies.