Vegetable oils and fats are important renewable raw materials for use by the biodiesel industry. One drawback of this industry is the large amounts of glycerol produced as a by-product. Consequently, crude glycerol is moving from a by-product to a residue. New industrial applications for this substance are required. A conversion of this by-product to allyl esters using various fatty materials in a two-step process is reported: After a simultaneous alcoholysis–chlorination reaction of vegetable oils and fats without a solvent, allyl esters were synthesized in a high yield by a rearrangement–elimination reaction using n-butanol as a solvent. All the reactions could be carried out using conventional heating or microwave irradiation with comparable results. Microwave irradiation allows for an important reduction in the reaction time. ; This work was supported in part by a Grant-in-Aid for the Secretaría de Estado de Política Científica y Tecnológica of the Spanish Ministry of Education and Culture (Contract grant number: CTQ2006-07451). The authors are grateful to the Comissionat per a Universitats i Recerca del Departament d’Innovació, Universitats i Empresa de la Generalitat de Catalunya and to the the European Social Fund (ESF) for the FI grant of Marc Escribà Gelonch