Bromotrimethylsilane (TMSBr) is a very efficient reagent in the solvent-free conversion of glycerol into bromohydrins, useful intermediates in the production of fine chemicals. As glycerol is a relevant by-product in biodiesel production, TMSBr has been also tested as a mediator in transesterification in acidic conditions, providing FAME from castor oil in good yields, along with bromohydrins from glycerol. Subsequently the glycerol conversion was optimized and depending on the reaction conditions, glycerol can be selectively converted into α-monobromohydrin (1-MBH) or α,γ-dibromohydrin (1,3-DBH) in very good yields.