The crystallization of Pd43Ni10Cu27P20 melts is studied during constant cooling and heating. Investigations are carried out on samples that are divided into several hundred particles which are fluxed in B2O3, The size of the particles is chosen in such a way that crystallization of individual particles can be observed, The cooling rate is varied between 0.3 K/s and 0.0016 K/s. The crystallization upon subsequent heating at 03 K/s is used to determine the fraction of particles that crystallize upon cooling. The critical cooling rate for some of the particles is 0.005 K/s. This is the lowest rate ever measured for a metallic system.