The increased life expectancy of adult individuals with developmental disabilities and the likelihood of parents having to continue caregiving into their old age is an emerging international issue which deserves investigation, especially concerning satisfaction with caregiving. Moreover, this needs to be assessed in different cultures in order to create a better understanding of how families are best supported in their lifelong caregiving. A sample of 408 parents was gathered in six cities across Iran with a son or daughter who had a confirmed developmental disability. Self-completed measures of satisfaction and stress were obtained along with demographic details of the child and family. Satisfaction with caring was generally positive and was similar for mothers and fathers, for older as well as for younger parents; and between different types of developmental disabilities. However, both personal and child satisfaction decreased when parents reported increased stress and when caring for teenage and adult offspring and those with behavior problems. Parents need to receive support to sustain their motivation and satisfaction with caregiving if their quality of life and that of their children with disabilities is to be maintained and enhanced across their lifespan.