CORNERSTONE IV, L.L.C.

   1


                             JOINT FILING AGREEMENT

                  This will confirm the agreement by and among all of the
undersigned that the Schedule 13D filed on or about this date with respect to
the beneficial ownership of the undersigned of Westaff, Inc. is being, and any
and all amendments to such Schedule may be, filed on behalf of each of the
undersigned. This Agreement may be executed in two or more counterparts, each
of which will be deemed an original, but all of which together shall constitute
one and the same instrument.

Dated:    March 15, 2000

                                    CORNERSTONE EQUITY INVESTORS IV, L.P

                                    By:  CORNERSTONE IV, L.L.C.
                                    Its:  General Partner

                                    By:     /s/ Xxxxxxx X. Xxxxxx
                                       -------------------------------------
                                             Name:  Xxxxxxx X. Xxxxxx
                                             Title: Managing Director

                                    CORNERSTONE IV, L.L.C.

                                    By:     /s/ Xxxxxxx X. Xxxxxx
                                       -------------------------------------
                                             Name:  Xxxxxxx X. Xxxxxx
                                             Title: Managing Director

                                    CENTRE CAPITAL INVESTORS III, L.P.

                                    By:  Centre Partners III, L.P,
                                          As general partner of such partnership
                                          By:  Centre Partners Management LLC,
                                               attorney-in-fact

                                             By:   /s/ Xxxxxx Xxxxxxxx
                                                ----------------------------
                                                  Name:  Xxxxxx Xxxxxxxx
                                                  Title: Managing Director

                                    CENTRE PARTNERS III, L.P.

                                    By:  Centre Partners Management LLC,
                                             attorney-in-fact

                                             By:     /s/  Xxxxxx Xxxxxxxx
                                                ----------------------------
                                                  Name:  Xxxxxx Xxxxxxxx
                                                  Title: Managing Director

                                    CENTRE PARTNERS III, L.L.C.

                                    By:     /s/ Xxxxxx Xxxxxxxx
                                       -------------------------------------
                                         Name:  Xxxxxx Xxxxxxxx
                                         Title: Managing Director

                                    WESTAFF ACQUISITION CORP.

                                    By:    /s/ Xxxxxxx X. Xxxxxx
                                       -------------------------------------
                                        Name:  Xxxxxxx X. Xxxxxx
                                        Title: President and Secretary