Professional development for teachers is recognized as a critical component of policies to increase the quality of teaching and learning in schools. In this context, the issue of sustainability is particular importance. The purpose of this research was to identify the factors affecting the sustainability of teachers' professional development programs. This research wasappliedin terms ofpurpose and qualitative methodbased on a meta synthesis approach. The statistical population of the research was all documents, articles, booklets, chapters and reports in Doaj, ResearchGate, MDPA, ScienceDirect, Emerald, Elsevier, Espriger, Taylor & Francis, Scincedo, Google Scholr,ProQuest databases, which after screening, the number 38 documents were selected for analysis. To analyze the data, qualitative content analysis and Maxqda 2020 software were used. The research findings were classified into 5 main categories (providing and developing infrastructures, Characteristics of the program, Characteristics of users, Characteristics of the organization and Characteristics of the external environment of organization) and 24 subcategories. Based on the results of this research, it can be concluded that various individual, organizational and environmental factors are effective in strengthening the sustainability of teachers' professional development programs, and during the design, implementation and evaluation of these programs, the way of communication and interaction of them with each othershould be considered to increase the sustainability of the programs and achieve the necessary productivity.