We present the case of a 41-yr-old homosexual man who was managed for suspected rectal cancer before lymphogranuloma venereum was clinically diagnosed. At first, he presented with constipation and tenesmus for several days. Upon rectal examination, the mass was palpated at 3 cm from the anal verge. Colonoscopy revealed a tumor of lower rectum, but multiple endoscopic biopsies were unable to reveal the nature of the tumor, so the pathologist just gave the diagnosis of a rectal pseudo-tumor. Positive chlamydial serology was found, and the final diagnosis was made. He was treated for Chlamydia trachomatis with Doxycycline, 100 mg twice daily for 21 days.