Joint ventures between the public and private sectors for large-scale mixed-use development projects stem from a widely used model conceived in the United States in the 1970s, with a specific focus on downtown redevelopment. Beginning in the 1990s, as more cities in the world experienced post-industrial transformation and public resources were dwindling, collaborative efforts by public and private partnerships offered significant and mutually-beneficial advantages in terms of efficiency, flexibility, and risk sharing principles for project delivery. This paper establishes a framework of key criteria for use in evaluating the effectiveness of public and private development as a vehicle for constructing and delivering the dual purposes of regeneration and sustainability for the mixed-use development in various urban fabrics. Two development projects are selected and examined as case studies: one from the European/British context and one from the United States. They are the Liverpool ONE scheme in Liverpool City Centre and the California Plaza development in Los Angeles. Although the projects and public and private joint ventures are site-specific and context-bound, a conceptual framework is important for both the public and private sectors to identify opportunities and avoid potential pitfalls. In this paper, through the comparative examination and analyses of institutional structures, financing arrangements, delivery mechanisms, channels of public participation, and the key milestones represented by physical characteristics identified within the development processes, the dynamics of public and private developments are examined. The paper compares the partnership models under the different regulatory regimes in the United States and Europe and evaluates the success of the two case studies both from the private sector and the public sector perspectives. It also summarizes the possible evaluative parameters including costs and benefits of each project relative to regeneration and sustainability, some of which promise value for universal application.