A novel method, based on superpotentials is proposed for obtaining the quas
inormal modes of anti-de Sitter black holes. This is inspired by the case o
f the three-dimensional BTZ black hole, where the quasi-normal modes can be
obtained exactly and are proportional to the surface gravity. Using this a
pproach, the quasi-normal modes of the five-dimensional Schwarzschild anti-
de Sitter black hole are computed numerically. The modes again seem to be p
roportional to the surface gravity for very small and very large black hole
s. They reflect the well known instability of small black holes in anti-de
Sitter space.