Thanks to novel approaches and emerging technologies, tissue engineering and regenerative medicine have made a great effort to regenerate damaged tissue or organ with no donor needed. The approaches involve two fundamental components: bioengineered scaffolds and stem cells. Bioengineered scaffolds which can also be enriched with bioactive molecules such as cytokines, growth factors, and so on have been fabricated using a wide range of synthetically or naturally derived biodegradable and biocompatible polymers. These scaffolds should support cell attachment, migration, proliferation, and/or differentiation by mimicking the duty of native extracellular matrix. Stem cells are the other significant players in formation of the neotissue. Stem cells, bone marrow, or adipose-derived mesenchymal stem cells, in particular, have been widely used for this purpose. Recently, investigators have preferred to use progenitor cells including cardiac and neural cells in tissue engineering and regenerative medicine applications. The synergy of the bioengineered scaffolds and autologous stem cells is crucial for the successful reconstruction of damaged or missing tissues.