This chapter gives an account of the newer developments on the synthesis and reactivity of phosphine chalcogenides, mainly oxides and sulfides. A series of new synthetic methods for phosphine oxides is discussed, followed by preparations utilizing simple P-reagents such as P(iii)- and P(v)-chlorides, and >P(O)H species. Their additions to unsaturated substrates and P–C coupling reactions, involving interesting variations, represent a hot topic. The modification of P-chalcogenides including deoxygenations are also shown. Optically active phosphine oxides and their complexes also form a usual part of this chapter.