Home interviews were given to 369 families of children (3-18 years old) with cystic fibrosis, cerebral palsy, myelodysplasia, and multiple physical handicaps to determine the impact of childhood disability on families. Results were compared with those of 465 control families who had one or more non-handicapped children in that age range. A cross sectional model was used to analyze results according to four successive outcomes of child disability: family cohesion, maternal distress, family repertoire of activities, and mastery. Results suggested that child disability did not directly influence maternal distress, but did indirectly affect distress via family repertoire and mastery. Results supported the hypothesis that a disabled child in the home has a significant negative effect on family repertoire of activities, which in turn affects the mother's sense of her mastery. A lack of mastery, in turn, is associated with distress. The overall picture of the interplay among variables was somewhat different for white and black families. The effect of childhood disability on family variables and on mastery was 3.5 times greater for black than for white mothers. (CL)