We examined whether changes in the frequency of contact with the social network (partner, children, grandchildren, other relatives, friends and colleagues) in a group of colorectal cancer patients were associated with survival. The study was based on a questionnaire survey from 1991. The study population consisted of 770 Danish colorectal cancer patients diagnosed in the period 1985-1990, and followed up for survival until March 2002. Using Cox regression analysis we found a significantly higher mortality among patients who had lost their partner before the operation compared to patients cohabiting with the same partner as before the operation (rate ratio (RR)=1.4, 95% confidence interval (CI): 1.1-1.8) possibly because of less active cancer treatment. This needs investigation in future studies. Contrary to expectations we also found a significantly higher mortality among patients reporting increased contact with their children compared to patients reporting unchanged contact frequency (RR=1.7, 95% CI: 1.3-2.4). However, a low physical functioning of the cancer patient may have confounded the latter result.