Lake Sturgeon Acipenser fulvescens, once widespread throughout North America, are now considered endangered in much of their natural range. However, recreational catch-and-release (C&R) fisheries targeting the Lake Sturgeon have developed in areas with strong populations. Here, we evaluated physiological and behavioral impairment of Lake Sturgeon after C&R angling. Fish were angled from the Winnipeg River and transferred to a holding pen to recover and facilitate serial sampling after angling. Measured physiological traits included blood osmolality, pH, glucose, and cortisol concentration. Behavioral impairment was measured as a binary score using reflex action mortality predictors in addition to ventilation rate. The effects of season and angler experience on these measured variables were assessed. Catch-and-release angling resulted in an immediate physiological stress response and behavioral impairment in all Lake Sturgeon regardless of treatment. Generally, we observed a recovery in acid-base balance, ion balance, and reflex impairment by 24 h; however, cortisol and glucose were elevated throughout the recovery period, possibly indicating interactive stressors of holding and repeat sampling. Angling in the summer period caused increased ventilation rate and decreased osmolality at all timepoints compared to angling in the spring. In comparison with experienced anglers, novice anglers caused higher reflex impairment in Lake Sturgeon immediately after capture. This is the first study to examine the response of wild Lake Sturgeon to C&R angling. Data show an apparent resilience of Lake Sturgeon to C&R and can be used to assess the validity of C&R as a management strategy in the conservation of Lake Sturgeon. The recent and widespread incorporation of catchand-release (C&R) angling into North American fisheries management has provided a vital tool for managing and conserving recreational fisheries and has offered a basis for sustainable use (Tufts et al. 2015). Catch-and-release fishing has the potential to reduce fish harvest without restricting recreational opportunities for anglers who are invested in the conservation of the fishery. Therefore, the concept of C&R fishing is rooted in conservation but operates under the assumption that released fish are not killed or otherwise impaired (Wydowski 1977); however, angling events can have lethal or sublethal effects on fish through delayed stress and injury (Arlinghaus et al. 2007).