Organic selenium reagents were successfully applied as building blocks in asymmetric reactions for their rich and versatile reactivity. The stereoselectivity can be controlled by the chiral selenium reagents or by the chirality of the reactants. A few examples of chiral diselenides employed as catalysts in asymmetric reactions were also reported. In the last years, vinyl selenones were rediscovered as useful building blocks for new asymmetric transformations. Various Michael initiated multiple bond-forming reactions and organocatalyzed processes are reported constructing heterocycles, natural products, and densely functionalized compounds. Further, the ease of handling, the mild reaction conditions, and the variety of possible applications make the vinylselenones particularly efficient for these cascade processes. This latter aspect, representing one of the most recent developments in the reactivity of organoselenium compounds, will be covered.