Abstract An efficient and sustainable microwave-assisted approach for the one-step preparation of a wide range of 1, 3, 5-triazinyl mono-and bisureas has been developed, combining solvent-free conditions and microwave irradiation. In these conditions the very unreactive amino groups of 1, 3, 5-triazine-2, 4-diamines successfully react with phenylisocyanate to yield selectively mono and bisureas.