Isolated peritoneal metastases of lung adenocarcinoma are very rare, even exceptional, occurring most often in the context of a multi-metastatic disease. This report presents a rare clinical case of isolated peritoneal metastasis from lung adenocarcinoma. We report a 56-year-old male who was monitored for lung adenocarcinoma whose evolution has been marked by an isolated metastatic recurrence in the peritoneum objectified by an abdominal-pelvic computed tomography (CT) and confirmed by a laparoscopy with abiopsy of the peritoneal nodules. The patient had received palliative chemotherapy with gemcitabine, cisplatin and bevacizumab. The evolution was marked by a progressive deterioration of the general condition and death two months after the third treatment cycle. Peritoneal carcinomatosis from lung adenocarcinoma is a very rare event, and is often associated with a poor prognosis.