Enzymatic acetylations of N-substituted cis- and trans-3,4-dihydroxypiperidine and hydrolysis of their diacetylated derivatives have been studied. High enantioselectivities are obtained with Pseudomonas cepacia lipase and Candida antarctica lipase B for the hydrolysis of the trans-derivative, while the cis-derivatives are not adequate substrates in the same biocatalytic conditions. The enantiopreference of these processes can be rationalized by means of a molecular modelling study.