Difficulties experienced by mothers caring for a child with cystic fibrosis were assessed. Difficulties were categorized as: (1) developmental, which included tasks generic to all families (bedtimes, socialization, siblings and communication with others); and (2) illness, which were especially pertinent to the care of the child with cystic fibrosis (mealtimes, physiotherapy and home-based medical care). Age differences were found in stresses associated with developmental routines, with mothers of younger children reporting more difficulties. With regard to illness routines, more difficulties were reported for children in better health (higher Shwachman scores). The data suggest that parents experience increasing difficulties in implementing home-based medical care where the child is in better health. Clinic staff need to be more aware of these difficulties and target information to parents appropriately.