Micrometer size plasmas, or microplasmas, find applications in pollution control, reduction, and prevention. The required nonthermal plasmas can be generated by either an electron beam or an electric discharge. The pulse widths and voltages necessary to generate these nonthermal plasmas are$10 ^-10$–$10 ^-8~ s$, and$10 ^3$–$10 ^4~ V$, respectively, depending on the application. The required energy is typically in the low$10 ^-3~ J$range. This paper presents a novel circuit design to generate high-voltage pulses with variable pulse widths and pulse rise and fall times in the low$10 ^-9~ s$regime. The circuit employs two parallel Marx Generators utilizing bipolar junction transistors (BJTs) as closing switches. The BJTs are operated in the avalanche mode to yield fast rise times. The design allows for positive or negative polarity pulses, and can easily be changed to yield higher or lower output voltage.