The study focused on the variables influencing the functioning of 62 families with MR (mentally retarded) persons, living at home, in various stages of the life cycle. Results demonstrated the importance of some father characteristics to maternal coping skills in two-parent households. Although mean maternal coping scores were not statistically different between two-parent and single-parent households, single mothers' coping skills showed strong negative associations with both the number of children in the household and the age of the mother. This was not true of mothers in two-parent households. Single-parent mothers also appeared to be considerably more dissatisfied with family functioning than mothers in two-parent households. The supportive role of older fathers in mothers' coping in two-parent households also was apparent. Clinical implications of the study point to the need for greater support for mothers of young children with MR, mothers who are sole caregivers, and parents with many children. Differential support to mothers and fathers of an MR person may be required over the life cycle.