This study examined the phenomenon of avoidance of family communication about cancer. Thirty-seven Stage III or IV lung cancer patients and 40 caregivers, including 24 primary and 16 secondary caregivers, were interviewed; a total of 26 families were studied. The interviews were audiotaped and transcribed. Analysis of the interviews indicated that two thirds of the families (65%) experienced communication problems. The avoidance of family communication was associated with several underlying thought processes: avoidance of psychological distress; desire for "mutual protection;" and belief in positive thinking. Family communication was further hindered by the increasing difficulty of issues inherent to late-stage cancer. The adverse impact of communication avoidance and the implications of our findings are discussed.