This letter describes the use of a power‐optimized cascode configuration for obtaining maximum output power at millimeter‐wave (mm‐wave) frequencies for a two‐way combined power amplifier (PA). The PA has been fabricated in a high‐speed InP double heterojunction bipolar transistor technology and has a total active emitter area of 68.4 μm2. The experimental results demonstrate a small signal gain of 9.8 dB and saturated output power of more than 18.6 dBm at 72 GHz with a peak power‐added efficiency of 12%. The benefits of the power optimized cascode configuration over the standard cascode configuration at mm‐wave frequencies are confirmed by both simulations and experimental results. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1178–1182, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27477