We prove that the equations of motion describing domain walls in a Wess-Zum
ino theory involving only one chiral matter multiplet can be factorized int
o first order Bogomol'nyi equations, so that all the topological defects ar
e of the Bogomol'nyi-Prasad-Sommerfield type. (C) 2001 Elsevier Science B.V
. All rights reserved.