We present experimental observations of ionization waves in pulsed hollow cathode capillary discharges. When the capillary shield is at the anode potential, an anode directed ionization wave, with characteristic speed∼107&hthinsp;m/s,is observed. When the capillary shield is at the cathode potential, a cathode directed slower ionization wave, with characteristic speed∼104&hthinsp;m/s,is observed. The several orders of magnitude difference in the ionization wave speed can be attributed to the different initial electric field configuration in both polarities. ©2001 American Institute of Physics.