In this protocol, we report a Mo-catalyzed anti-dihydroxylation of secondary allylic alcohols, providing a general method for the preparation of 1,2,3-triols bearing up to three continuous stereocenters with excellent diastereocontrol. The mechanistic studies reveal that this dihydroxylation reaction consists of two steps and up to excellent diastereomeric ratios of the final triol products can be achieved due to the high level of both diastereocontrol in the initial epoxidation and regiocontrol in the following hydrolysis in situ.