Clinical follow‐up data of 276 colorectal adenocarcinoma patients treated in Kuopio University Hospital between 1976 and 1986 and followed up for a mean of 14 years were analysed. The clinical findings were correlated with tumour‐infiltrating lymphocytes (TILs) and with histological and quantitative factors including nuclear parameters and volume‐corrected mitotic index. In univariate survival analysis, TNM classification, Dukes' stage, histological grade, and TILs were significant predictors of survival. TNM classification, Dukes' stage, and TILs also predicted recurrence‐free survival. In multivariate analysis, TILs were an independent prognostic factor of survival in all cases, as well as in patients with T1‐4N0‐3M0 and T1‐4N1‐3M1. TILs also independently predicted recurrence‐free survival. TILs can provide important prognostic information in colorectal cancer to be used in evaluating for adjuvant therapy in different tumour stages. © 1997 John Wiley & Sons, Ltd.