  Detecting and studying pulsars above a few GHz in the radio band is
challenging due to the typical faintness of pulsar radio emission, their steep
spectra, and the lack of observatories with sufficient sensitivity operating at
high frequency ranges. Despite the difficulty, the observations of pulsars at
high radio frequencies are valuable because they can help us to understand the
radio emission process, complete a census of the Galactic pulsar population,
and possibly discover the elusive population in the Galactic Centre, where
low-frequency observations have problems due to the strong scattering. During
the decades of the 1990s and 2000s, the availability of sensitive
instrumentation allowed for the detection of a small sample of pulsars above
10$\,$GHz, and for the first time in the millimetre band. Recently, new
attempts between 3 and 1$\,$mm ($\approx$86$-$300$\,$GHz) have resulted in the
detections of a pulsar and a magnetar up to the highest radio frequencies to
date, reaching 291$\,$GHz (1.03$\,$mm). The efforts continue, and the advent of
new or upgraded millimetre facilities like the IRAM 30-m, NOEMA, the LMT, and
ALMA, warrants a new era of high-sensitivity millimetre pulsar astronomy in the
upcoming years.
