Embryonic development and differentiation are controlled largely by external stimuli. Mechanical forces, such as those exerted by the surrounding cells and tissues, gravity and substrate rigidity, have been shown to affect cell morphology and spreading, thus triggering signaling pathways that dictate their development. These mechanosignaling pathways play important roles in cellular differentiation and the determination of cell fate. In this review, we discuss the effects of external environmental stimuli on cell differentiation and how this affects pluripotency, as well as the key molecules and pathways involved in mechanosignaling, particularly in relation to embryonic stem cells. Advances in experimental techniques and devices used to study the different aspects of mechanobiology are also examined. Finally, the effects of mechanical stress on the initiation and maintenance of pathological processes such as cancer, as well as their implications for prognosis and possible therapies are discussed.