Background <p>Femoral hernia represents a rare form of abdominal hernia. The protrusion of peritoneal contents through the femoral ring may lead to incarceration, preventing their return to the peritoneal cavity and potentially resulting in necrosis, which can cause severe complications. Cases involving femoral hernias with necrotic sacs accompanied by purulent effusion are exceedingly rare.</p> Case presentation <p>This report details a rare case of a left incarcerated femoral hernia with purulent effusion secondary to a periappendiceal abscess. The left femoral hernia sac exhibited incarcerated necrosis with purulent effusion. Accurate preoperative assessment, decisive surgical intervention, appropriate timing of the operation, and smooth postoperative recovery ensured that the patient avoided serious complications and was discharged without incident.</p> Conclusion <p>Femoral hernias with necrosis of the hernia sac secondary to periappendiceal abscesses are uncommon and prone to misdiagnosis or mistreatment, which could result in adverse outcomes detrimental to patient recovery. This case is reported to emphasize the importance of comprehensive analysis during the treatment process for similar conditions, ensuring appropriate therapeutic strategies are implemented to prevent complications, particularly in elderly patients.</p>