Recent advances in stem cell biology may make possible new approaches for the treatment of a number of diseases including cardiovascular disease, neurodegenerative disease, musculoskeletal disease, diabetes and cancer. These approaches could involve cell replacement therapy and / or drug treatment to stimulate the body's own regenerative capabilities by promoting survival, migration / homing, proliferation, and differentiation of endogenous stem / progenitor cells. However, such approaches will require identification of renewable cell sources of engraftable functional cells, an improved ability to manipulate their proliferation and differentiation, as well as a better understanding of the signaling pathways that control their fate. Cell-based phenotypic and pathway-specific screens of synthetic small molecules and natural products have historically provided useful chemical ligands to modulate and / or study complex cellular processes, and recently provided a number of small molecules that can be used to selectively regulate stem cell fate and developmental signaling pathways. Such molecules will likely provide new insights into stem cell biology, and may ultimately contribute to effective medicines for tissue repair and regeneration.