<p></p><p>This review is a follow-up to our previous article on the role of diselenides in the synthesis of heterocycles (2008–2018).¹The earlier review was based on 83 literature sources. However, in the past seven years, the utilization of diorganyl diselenides in the formation and modification of heterocycles has significantly expanded, with over 200 new reports now available. Given this rapid development, we decided to provide an updated review to assist scientists across all areas of synthetic chemistry in exploring the unique potential of the diselenide moiety as a starting material for crafting sophisticated heterocycles. Herein, we discuss recent advancements in the synthesis of heteroarylselenides from diselenides, highlighting a range of methodologies. These include electrophilic reactions involving the formation of selanyl halides, oxidant-induced transformations, transition-metal-catalyzed processes, as well as photochemical strategies.</p>