An objective is to provide a pressure-sensitive adhesive composition which shows pressure-sensitive adhesive properties at ordinary temperature, has the ability to cure upon irradiation and after photocure exhibits improved bond strength relative to high-polarity adherends, such as PET, PVC and metals, and improved moist heat-resisting bond strength, a pressure-sensitive adhesive and a pressure-sensitive adhesive sheet obtained from the aforementioned pressure-sensitive adhesive composition. A photocurable pressure-sensitive adhesive composition containing a polyester resin having a glass transition temperature (Tg) of 25° C. or above, a cationically photopolymerizable compound and a cationic photoinitiator.