Pathological prognostic factors of rectal adenocarcinoma were studied retrospectively in 173 patients who underwent curative resection between 1970 and 1980. Analysis was mono- and multifactorial. Minimal and median follow-up were 24 and 66 months respectively. Three factors had a favorable influence on the local failure (LF) and distant metastasis (DM) risks: length of the tumor less than 2 cm; polypoid aspect; Astler-Coller's stage A. Four factors increased the LF risks: perineural invasion (LF = 57 p. 100); poorly differentiated or colloid tumors (LF = 50 p. 100); lymph node metastasis (LF: 43 p. 100); lymphatic invasion (LF = 36 p. 100). Two factors increased the DM risks: perineural invasion (DM = 43 p. 100); lymph node metastasis (DM = 37 p. 100). The multifactorial analysis showed that the risk factors were the same for LF as for DM. Perineural invasion (p less than 0.001), lymph node metastasis (p less than 0.002), level of extension of the tumor in the rectal wall (p = 0.005) were the most important factors for local recurrences. Lymph node metastasis (p less than 0.001), perineural invasion (p = 0.03) and level of extension in the wall (p = 0.05) were the most important factors for DM. These data suggest that a failure risks scale may be established and can be of help in stratifying patients in adjuvant treatment studies.