One-pot synthesis of cyanamides from isoselenocyanates through deselenisation promoted by ionic liquid-supported hypervalent iodine(III) reagent 1-(4-diacetoxyiodobenzyl)-3-methylimidazolium tetrafluoroborate ([dibmim]+[BF4]−) was developed. This approach provided a simple, mild and environmentally benign way to construct cyanamides in good yields. Moreover, powder Se and [dibmim]+[BF4]− could be easily recycled. It was the first example of [dibmim]+[BF4]− to be used as a deselenising agent.