New pulsar observations at 8.35 GHz with the newly built highly sensitive receiver of the Effelsberg 100-m Radio Telescope are reported. They resulted in the first detection of 3 millisecond pulsars J1713+0747, B1855+09 and J2145-0750 at this high frequency. The measured flux densities indicate that the spectrum of all three pulsars follows a single power law. PSR B1855+09 shows a significant increase of the Interpulse-to-Mainpulse amplitude ratio at high frequencies.