Quantum dots (QDs) are a novel class of inorganic fluorophores, which are gaining widespread recognition as a result of their exceptional photophysical properties. They are rapidly being integrated into existing and emerging technologies, and could play an important role in many areas in the future. Significant phenomena, such as photoactivation, are still unknown and must be understood and more fully defined before they can be widely validated. This review provides an overview of the photoactivation process of quantum dots in a systematic way, covering QD characteristics, solubilisation strategies, and a description of different photoactivation mechanisms, depending on the type of QDs and their surrounding environment.