A smart city is one of the latest concepts in the development of modern cities. It has evolved from the foregoing smart cities 1.0 and 2.0 to the smart city 3.0, where members of the local community play the main role as not only the recipients of the introduced changes and modern technology, but also as the creators of urban space. One of the goals of a smart city 3.0 is to promote sustainable urban development by improving the quality of life, enhancing social participation, and involving local community members in planning and decision-making processes. This study set out to determine the role and significance of e-participation methods in the smart city concept. The results of questionnaires exploring the importance of e-participation in urban development are presented. The paper also discusses changes in the availability of information and communication technologies (ICT) in Poland. The secondary goal was to present the geo-questionnaire and Public Participation GIS (PPGIS) as modern research tools. Internet tools based on geoinformation systems have considerable potential for mobilizing social participation in spatial planning (Public Participation GIS). The present study postulates the need for modern social participation methods in shaping urban space and promoting the sustainable development of cities. The study highlights the main challenges in the research process. The cooperation between the authorities and the citizens contributes to the development of a civil society, informed decision-making, social involvement in public life, and more effective governance at the local, regional, and national level. Measures that foster cooperation between the authorities and local communities, the use of information and communication technologies (ICT), and growing social awareness and social participation in managing development are the components of a modern smart city and the building blocks of an e-society. The study also revealed positive changes in access to ICT and their contribution to bridging the digital divide in Poland. Higher levels of social awareness regarding participation and e-participation promote the growth of smart cities.