Available population based survival statistics for colorectal cancers were compared. The results based on relative survival rates showed similar data in Finland, Norway, Geneva and Cote d'Or. The survival rates were lower in Great Britain and Iceland. Several factors complicate survival comparisons: age, exact localization of the tumour, definitions and distribution of tumour stages. Adjustment of these factors is necessary. If their definitions differ, no conclusion can be based upon the data. Population based survival figures provide public health authorities with a basis for monitoring cancer patient care. They are also useful for assessing the resources required for cancer treatment, follow-up and rehabilitation. They provide clinicians with survival data for reference.