Association of adenocarcinoma and tuberculosis (TB) of the sigmoid colon is a rare clinical condition even in an endemic country as Romania, with challenging diagnosis and treatment. Case report. We present the case of a 57-year-old female patient who was admitted on emergency basis for a diagnosis of obstructive sigmoid adenocarcinoma. The patient was operated on and it an obstructive sigmoid tumor with serosal invasion, adherent (invading) to the body of uterus and left adnexa and urinary bladder serosa, no liver or peritoneal metastases. A sigmoidectomy was performed "en bloc" with subtotal hysterectomy, left adnexectomy and extramucosal cistectomy. The histopathological exam showed a moderately differentiated, ulcerated adenocarcinoma, widely infiltrating the colon wall invading the myometrium. Ziehl Neelsen (ZN) stain identified the presence of metachromatic bacillary structures in the colonic wall, lymph nodes and adnexal areas. Postoperative course was uneventful and the patient was discharged 10 days postoperatively in good clinical condition. After one year when the patient completed the full course of anti-tubercular drugs, a thorough work-up was performed. Colonoscopy, CT of the thorax, abdomen, pelvis showed no signs of recurrence while tumoral marker CEA (1.62 ng/ml - n<3.4) and QFT (Quantiferon-TB Gold) test were within normal range. Discussion and conclusion. Although digestive tuberculosis is included in differential diagnosis for those patients presenting abdominal pain or obstructive digestive symptoms in endemic regions, in this case the absence of TB infection criteria and positive endoscopic biopsy for colonic adenocarcinoma did not allow a complete pre- or perioperative diagnosis.