Abstract. Benzotriazole is a very useful synthetic auxiliary with versatile applications in organic chemistry. We have used benzotriazole in the synthesis of various heterocyclic compounds (benzoxazine, quinazoline, triazinetrione, hydantoin, oxadiazine and diazepane derivatives), amino acid derivatives, carbamates, ureas, semicarbazides, carbazides, sulfonylureas, sulfonylcarbazides, hydantoic acids, nonsteroidal antiinflammatory drug (NSAID) and primaquine derivatives, polymer-drug and thiomer-drug conjugates. The results have been published in more than 30 papers and here we give an overview of all syntheses. (doi: 10.5562/cca2124)