Yellowtail kingfish (Seriola lalandi) are angled throughout their global distribution and released in large numbers under the unsubstantiatedassumption of few impacts. The validity of this supposition was tested for southeastern Australian stocks. In all, 54 fishwere angled and released into cages with 36 controls and monitored for 5 d. Of the angled fish, 15% died, mostly as a consequenceof gill-hooking and the associated physiological and mechanical damage. A biotelemetry experiment was then performed to determineif cutting the line on gill-hooked fish could improve their post-release fate. The attachment of transmitters was validated in anaquarium experiment before 12 jaw- and 10 gill-hooked fish were tagged, released, and tracked. One gill-hooked fish was detectedmotionless within 10 min, and another was last detected 7 min after release; both presumed dead. No jaw-hooked fish died withinthe first 24 h. The remaining fish were last detected between 3 and 49 d after release and, apart from subtle differences in theirshort-term responses, maintained similar wide-ranging movements and accelerations. The results justify cutting the line on deephookedfish to minimize post-release mortality and illustrate the utility of combining confinement and biotelemetry studies toassess the fate of released fish.