Selenium-containing heterocycles have been interested because of their unique reactivity and potential biological activity. Recently, several selenium-containing heterocycles bearing an exocyclic imine have been synthesized by isoselenocyanates. Here we report the synthesis of 2-imino-1,3-thiaselenolanes. The reaction of isoselenocyanates with allyl mercaptan afforded S-allyl-selenothiocarbamates. Then 2-imino-1,3-thiaselenolanes were obtained as Z/E mixture at the imine position via iodocyclization reaction. Additionally, we also investigated the Z/E isomerization of the related cyclization reactions.