AIM: To evaluate the efficacy of postoperative serial assay of carcinoembryonic antigen (CEA) and cytokeratins for the detection of recurrent disease in patients with colorectal adenocarcinoma after radical surgery.METHODS: Between 1993 and 2000, 120 patients with colorectal adenocarcinoma underwent radical surgery in the Department of Surgical Gastroenterology, Federal University of Sao Paulo-Escola Paulista de Medicina,Sao Paulo, Brazil. Periodic postoperative evaluation was performed by assaying markers in peripheral serum,colonoscopy and imaging examination. Presence of CEA was detected using the Delfia(R) method with 5 μg/L threshold, and cytokeratins using the LIA-mat(R) TPA-M Prolifigen(R) method with 72 U/L threshold.RESULTS: In the first postoperative year, patients without recurrent disease had normal levels of CEA (1.5 ± 0.9 μg/L) and monoclonal tissue polypeptide antigen-M (TPA-M, 64.4 ± 47.8 U/L), while patients with recurrences had high levels of CEA (6.9 ± 9.8 μg/L,P ＜ 0.01) and TPA-M (192.2 ± 328.8 U/L, P ＜ 0.05).During the second postoperative year, patients without tumor recurrence had normal levels of CEA (2.0 ± 1.8μg/L) and TPA-M (50.8 ± 38.4 U/L), while patients with recurrence had high levels of CEA (66.3 ± 130.8 μg/L, P ＜ 0.01) and TPA-M (442.7 ± 652.8 U/L, P ＜ 0.05). The mean follow-up time was 22.3 mo. There was recurrence in 23 cases. Five reoperations were performed without achieving radical excision. Rises in tumor marker levels preceded identification of recurrences: CEA in seven (30％) and TPA-M in eleven individuals (48％).CONCLUSION: Intensive follow-up by serial assay of CEA and cytokeratins allows early detection of colorectal neoplasm recurrence.