Psychological evaluation of 43 families, each with a child with cystic fibrosis, is reported. Personality testing of the parents showed that 32% of the fathers and 22% of the mothers obtained scores in the range suggestive of emotional disturbance. The Family-Concept O Sort assessment of family interaction indicated that the primary effect of having a child with cystic fibrosis was in terms of decreased family satisfaction and family adjustment. The results do not support previous estimates of an increased incidence of emotional disturbance in children with cystic fibrosis. Evidence for negative psychological impact of chronic illness on sibling development was also lacking. Future research would benefit from a focus on the strengths and resilience of children with cystic fibrosis and their families.