Symbolic Lie algebras manipulations using COMMON LISP. We present a description and an implementation of a program in COMMON LISP to perform symbolic computations in a given Lie algebra. Using the general definitions of vector space Lie algebra and enveloping algebra, the program is able to compute commutators, to evaluate similarity transformations and the general Baker-Campbell-Hausdorff formula. All the computations are exact, including numerical coefficients. For the interactive user an optional menu facility and online help are available. LISP knowledge is unnecessary.par [The program called “VSPLAD” (Catalogue number: ABFW) is obtainable from: CPC Program Library, Queen’s University of Belfast, N. Ireland].