In a previous study we stated the existence of two distinct stress coping strategies in a hatchery reared brown trout population using a method were each fish faced a series of tests, each test including quantifiable key characteristics of stress coping strategies; 1) Physiological stress response after confinement, 2) Behavioural response during hypoxia and 3) aggression towards a conspecific intruder. Here, using the same method, we show that five brown trout populations with different origin, but reared under the same conditions, differ in their physiological stress response, behaviour during hypoxia and aggression. If individuals are classified as proactive and reactive based on post stress blood plasma noradrenaline levels (high noradrenaline is a key characteristic of proactive individuals) the frequency distribution implies that populations with hatchery origin are biased towards having higher numbers of proactive individuals than do other populations in this study. This study was supported by the Swedish Research Council for Environment, Agriculture Sciences and Spatial Planning (FORMAS)