In the design process of open spaces within residential apartments, little attention is paid to children and their attitude to the environment is often ignored. Children, especially those who live in high-rise apartments, were found to have less connection with nature. Children supposedly need to engage in physical activities within outdoor areas, but urban planners, with the approval of managers or parents, must adequately design the open space for children. This paper initially reviews different research in this area. It consequently attempts to evaluate parental satisfaction regarding children's connectivity to open spaces as a dependent variable, and their preferences and perception of safety as independent variables. The research method is based on a questionnaire survey addressed to 261 parents and adults, in two localities in Tehran, Iran. The result of this research shows that parental attitude to open space has an effect on children's outdoor activities. Moreover, parents with young children express lower satisfaction to open spaces than those adults without young children. Families with children need open spaces in residential high-rise apartments for their siblings’ physical activities, and the designers should consider such an important need.