1,5-Disubstitutedhydantoins/thiohydantoins 3a-p have been synthesized in 8l-95% yield by a microwave-promoted solvent-free condensation of arylglyoxals 1 and phenylurea/thiourea 2 using PPE as a reaction mediator. This method can be extended towards the parallel synthesis of 3. The workup is simple and involves treatment with ice-cold water.