Smart city is one of the powerful concepts that have deep impacts on contemporary cities. Planners, developers, and authorities thought that change to smart city using information and communication technologies could enhance the quality of urban life; rather, still their impact on long-term change of social life and consequently on social sustainability in contemporary cities is not fully investigated. Some scholars argued that moving from conventional to smart city will greatly encourage social activities in urban space. In contrast, this research argues that increasing people familiarity with ICT will create new urban behavioral patterns that could build great barrier to urban social sustainability. It aims to take the proper precautions for any expected negative impacts on social sustainability. The research adopts a case study of three parks in Madinaty, Egypt. It aims to find the correlation exists between people familiarity with ICT and changing behavioral patterns. It is concluded that smart cities have great consequences on changing patterns of urban behavior, city spatial structure and urban social sustainability. The research recommends smart design guidelines using social, communicative, and collective activities to mitigate any expected social risks of smartness.