This study investigates the relation of communication around parental multiple sclerosis (MS) to family dysfunction and mental health problems of the children in Greek families. Fifty-six families with a parent with MS were studied regarding emotional well-being of children, parental depression, family functioning, and illness' related impairment, correlated to the amount of information about parental illness provided to children. Significant differences were found in three dimensions of child psychopathology on maternal scores of Child Behavior Checklist, between children who had partial information about parental illness and the other two groups of children who had explicit or no information at all. Differences were also observed in children's scores on (Youth Self Report) social problems between the same groups. The finding that children who had only partial information about their parents' illness presented more problems, illustrates the importance of "how, what, and how much" of information is communicated to children. Clinical implications are discussed in terms of the families' difficulties with communicating parental illness with their children and possible need for professional support.