Objectives: The responsiveness of health system refers to the ability of a health system to meet the legitimate expectations of populations for the non-health enhancing aspects of the health system. It is a goal of health systems, which can be measured in terms of its level and its distribution across a population. The philosophy behind the measurement of responsiveness is to get the best available data on responsiveness for policy making. Responsiveness level is not an enough measure for policy making. Equality in responsiveness is another measure which must be accompanied with its level. Some studies have shown that there could be poorer quality of services offered to individuals with developmental disabilities as compared to normal population. However there have been no comprehensive evaluations of quality and equality of care for these individuals in Iran .To fill this gap we evaluated these children’s need by a new kind of evidence-based research tool to assess the equality in delivery of appropriate health care services. Methods: Children with developmental disability (cerebral palsy, mental retardation, congenital disorders) in the age group of 14 years old and younger who lived with their parents were considered as our study population. The study was carried out in all of the day cares which take care of children with developmental disability and give educational and rehabilitation services to these children in Tehran in 2005-2006. Mental illness of parent was considered as an exclusion criterion. Systematic random sampling was used to select 120 names from the list of 1000 children who had file in these daycares for these children.110 parents (0-14year-old children with developmental disability) participated in a cross-sectional studies .The translated WHO (World Health Organization) proposed questionnaire was used for interview with these children’s parents. The Gini coefficient was used to show inequality in responsiveness, this measures focus on differences in responsiveness between every pair of individuals in the population. This index is between 0 and 1.The greater the Gini, the greater the dispersion and the greater inequality. .All analyses were performed using STATA software version 8. Findings: The average response rate was 95%. (3% refused to participate in interview, 2%children did not have any parent or guardians). The children were 60% mild retarded and 40% moderate retarded. Children mean age was 7.7(7.1- 8.3) and52% were female. 39% of surveyed parents reported poor health system responsiveness for their children. There were no differences for reporting poor responsiveness among parents whose children have mild or moderate retarded and parents who have son or daughter with developmental disability. Parents with education more than diploma were more likely than less educated parents to report poor overall responsiveness however, these hypotheses were not confirmed by statistical tests. The over all responsiveness was 61±4.7.The Gini coefficient for responsiveness range from 0.2 (0.17-0.23) in out patient services to 0.28 (0.19-0.36) for inpatient services. There were no significant difference between responsiveness and child sex, child disability and parent’s education. Inequality in responsiveness within these children was not related to the socioeconomic status of their family. Results: There is inequality in care system responsiveness within these children. This study is only the first step towards policy dialogue and development, which shows care system responsiveness to these children, requires improvements in certain areas in order to meet one of the basic goals of health systems