Plasma formation in micro- and nano-scales enables an ultrahigh-dv/dt picosecond switching in an integrated circuit form factor. Such on-chip plasma devices could provide a transformative approach to achieving high-power levels at very high frequencies, far surpassing the best performance of conventional III-V electronics. In this work, we demonstrate the application of scaled-up nano- and microplasma switches as discrete devices in high-performance picosecond pulsed-power sources. A prototype circuit, utilizing the fabricated plasma devices operating as the switch, shows a high voltage-rising-rate beyond 10 kV ns−1 at 15 kW peak power. The pulsed-power source exhibits a sub-100 ps rise-time (without de-embedding). The device has the capability of reaching exceptionally high current densities up to 325 A mm−1. The switches are compatible with planar semiconductor fabrication, enabling their integration with other electronic devices and microwave components, which opens pathways towards the future ultrahigh power density picosecond pulsed-power sources.