This paper describes experiments in which acoustic emission ( AE) was monitored in samples of hydrided Zr-2.5 wt% Nb alloy tubes under applied diametric load. These hydrides form brittle platelets in the body of the alloy. The results are compared to those from samples of unhydrided Zr-Nb alloy tubes. It is shown that it is possible to discriminate between the AE originating from the hydride platelets and that from the metal alloy, as they appear to have distinct characteristics.