This study compared the adjustment of mothers and fathers who have a child with cystic fibrosis On most scales mothers, but not fathers, were found to have significantly poorer mental health than the general population Both mothers and fathers' perceptions of the stresses associated with rearing children with cystic fibrosos were related to their mental health Fathers mental health was also related to their wives' concerns about rearing children with cystic fibrosis The support of fathers appeared to protect mothers from the stress associated with cystic fibrosis, especially when fathers placed a high value on child-rearing activities.