The rapid development of two-dimensional (2D) transition-metal dichal-cogenides has been possible owing to their special structures and remarkable proper-ties.In particular,palladium diselenide(PdSe2) with a novel pentagonal structure and unique physical characteristics have recently attracted extensive research inter-est.Consequently,tremendous research progress has been achieved regarding the physics,chemistry,and electronics of PdSe2.Accordingly,in this review,we recapitulate and summarize the most recent research on PdSe2,including its structure,properties,synthesis,and appli-cations.First,a mechanical exfoliation method to obtain PdSe2 nanosheets is introduced,and large-area synthesis strate-gies are explained with respect to chemical vapor deposition and metal selenization.Next,the electronic and optoelectronic properties of PdSe2 and related hetero-structures,such as field-effect transistors,photodetectors,sensors,and thermoelec-tric devices,are discussed.Subsequently,the integration of systems into infrared image sensors on the basis of PdSe2 van der Waals heterostructures is explored.Finally,future opportunities are highlighted to serve as a general guide for physicists,chemists,materials scientists,and engineers.Therefore,this com-prehensive review may shed light on the research conducted by the 2D material community.