We study BPS domain wall solutions of 5-dimensional N = 2 supergravity wher
e isometries of the hypermultiplet geometry have been gauged. We derive the
corresponding supersymmetric ow equations and define an appropriate c-func
tion. As an example we discuss a domain wall solution of Freedman, Gubser,
Pilch and Warner which is related to a RG-flow in a dual superconformal fie
ld theory.