The test results from two, special ignitron tubes exposed to axial magnetic fields are described. The experiments were made with a capacitor bank with 2.56 mF total capacitance and 128 KJ maximum energy at 10 kV. To study the effects of axial magnetic fields on the switching characteristics, including the self breakdown voltage of the tubes, the test specimens were mounted inside 4 high-power, water cooled electro-magnets. The highest magnetic field which can be generated by this arrangement is 0.7 Tesla for conduction tests and 1.0 Tesla for high-voltage tests. The test results include voltage and current measurements along with optical diagnostics performed on a special tube which provides optical access to the discharge volume. The ignitron tubes tested were a small, glass-walled tube and one experimental size D tube with stainless steel walls, both manufactured by National Electronics/Division of Richardson Electronics. The optical diagnostics were performed with a mechanical high speed camera and an image converter camera in streak and framing modes.