--- - |2+ Abstract Objective From a self‐determination theory perspective, individuals are assumed to benefit and suffer from, respectively, the satisfaction and frustration of the psychological need for autonomy, even if they score low on autonomy strength. Yet, previous studies on need strength are scarce, operationalized need strength differently, and produced inconsistent findings. Method In two studies among 224 South African adults (Mage = 24.13, SD = 4.25; 54.0% male) and 156 Belgian prisoners (Mage = 38.60, SD = 11.68; 88.5% male), we investigated the moderating role of autonomy valuation and desire in the relations of autonomy satisfaction and frustration with a variety of well‐being and ill‐being indicators. Results Study 1 provided some evidence for the moderating role of mostly explicit autonomy desire (rather than explicit autonomy valuation). In Study 2, neither explicit nor implicit autonomy desire played a consistent moderating role. Conclusions Overall, these findings are congruent with a moderate (albeit not with a strong) interpretation of the universality claim made within self‐determination theory, provide initial evidence for a differentiation between deficit‐based and growth‐oriented interpersonal differences in need strength, and indicate that the potential moderating role of need strength deserves continued attention before any firm conclusions can be drawn. - Journal of Personality, EarlyView.