This study analyzed the psychological adjustment of parents of children and adolescents with type 1 diabetes (T1D) and examined whether family cohesion and parental adjustment were connected through the perceived impact of this condition on family functioning, as well as whether these links varied according to the child's age. In total, 104 parents of children (8-12 years old) and adolescents (13-18 years old) with T1D and 142 parents of healthy children and adolescents completed self-report measures of family cohesion, parental stress, quality of life (QOL), anxious and depressive symptoms, and perceived impact of chronic illness. The results indicated that the parents of children and adolescents with T1D were more anxious and perceived less family cohesion than the parents of healthy children and adolescents. No significant differences were found on depressive symptoms, QOL, and parental stress. The hypothesized moderated mediation model showed that parents who perceived their family environments as more supportive and caring tended to evaluate the impact of T1D on their families less negatively; in turn, this perception was associated with better QOL and less parental stress and anxious and depressive symptoms. These associations were independent of the children's age. Based on a risk and resistance framework, this study highlighted the relevance of the perceived impact of T1D on the family as a mechanism explaining the link between cohesion and parental adjustment. Family-centered interventions that help parents better cope with the demands of T1D and help family members be more supportive of each other seem to be particularly useful in this context.