Problem-Based Learning (PBL) forges effective communications between adult (communicational and pedagogical workers and parents) and at-risk youth (jeopardizing their present and future adjustments) to explore their engagements with community activism engaging in building their communities. PBL is vital for them to be engaged citizens, informed individuals and dynamic members of their society. This paper, therefore, introduces a theoretical approach for undeveloped, developing and developed countries to understand effective practices in developing democratic adult and at-risk youth communications in social justice. This framework emphasizes how PBL fosters multi-generational Communications and facilitative relationships between them to implement collective action. Also, this framework focuses on promoting dialogue amongst adult working with at-risk youth to improve their critical thinking skills by owning knowledge acquisitions. Developing these strong engagements between them brings about dialogical and democratic changes in communities that this framework provides adults and at-risk youth with inexpensive communication milieus to develop their common visions of social justice, and be engaged as part of a community working toward these visions. The main purpose of this paper, therefore, is to explore and discuss the main features of PBL to promote democratic adult and at-risk youth communications to build global knowledge networks and authentic learning milieus to bring democratic changes in their communities; to understand critical participation possibilities and potentials about social justice issues for lifelong learning; to recreate dialogical and democratic forms of pedagogy and community engagement; and explore powerful democratic communicational practices.