Abstract: Open public green spaces (OPGSs), such as parks and gardens, sports facilities and green corridors, play a significant role towards providing environmental, social, and economic functions and benefits to communities. Environmentally, they are air and water purification, wind and noise filtering, microclimate stabilization. In addition, they reduce stress, rejuvenate people, and provide peacefulness. Socially, OPGSs encourage the use of outdoor spaces, increase social integration and interaction among neighbors. Finally, its economic services include air purification by trees that reduces costs of pollution prevention; promotion of city as a tourist destination; and increase of property values. However, literature review and case studies showed that OPGSs are not fully satisfying their intended functions and benefits to communities. As an approach for increasing the sustainability of OPGSs, this paper aims to investigate the causes of inefficient use of OPGSs in Egypt. A research methodology based on literature review, is designed to build a comprehensive background of the research topic through reviewing the definition of OPGSs, functions and benefits of them as well as identifying the causes of inefficient use of OPGSs.The importance of this research emerges from the need to improve the environment, social and economic role of OPGSs and increase its sustainability. In addition, it raises the awareness of designers and proposes a criterion and guidelines to be considered during the design of OPGSs.