Transanal endoscopic microsurgery (TEM/TEO) is a standard treatment for rectal adenomas but can also be used for selected malignant tumors. Rectal adenomas, selected adenocarcinomas and carcinoids were chosen for operations. Preoperative work-up included: digital rectal examination, rectoscopy with biopsy, colonoscopy, EUS, pelvic CT (MRI). Two hundred and two patients [mean age of 62.4 ± 10.3 (33-86)] had TEO. The mean size ± SD of tumors was 3.2 ± 1.4 cm (0.6-8.0). Mean distance from anal verge and dental line was 7.1 ± 2.4 cm (2.5-14.0) and 4.6 ± 2.6 cm (0.5-12.0), respectively. Preoperative biopsy revealed: adenoma--156/202 (77.2%), adenocarcinoma--39/202 (19.3%) and carcinoid--7/202 (3.5%). The median operating time was 40 (20-180) min. Tumor-free margins were obtained in 200/202 (99%) operative specimens, 2/202 (1.0%) cases tumors were fragmented. Morbidity was 7/202 (3.5%). Pathological investigation revealed: adenoma in 109/202 (54.0%) cases, adenocarcinoma stage Tis, T1, T2 and T3 in 86/202 (42.5%), carcinoid in 5/202 (2.5%), neurilemoma in 1/202 (0.5%), neurofibroma in 1/202 (0.5%). One hundred and two patients had follow-up (95%). Median follow-up at 20 (1-41) months; 3/192 patients with adenocarcinoma, 1/192 patient with adenoma and 1/192 patient with carcinoid had local recurrence. Thus, transanal endoscopic microsurgery for rectal adenomas and selected malignant tumors is associated with low morbidity and low recurrents rates.