While avoidance can be a useful coping mechanism for those with anxiety, excessive or persistent avoidance can become a debilitating symptom of anxiety-related disorders. The transition from adaptive to maladaptive avoidance remains poorly understood, but stress is regarded as a potential contributing factor. This study investigates the effects of chronic restraint stress on two active avoidance procedures: two-way active avoidance (2WAA) and platform-mediated avoidance (PMA). In the latter, avoidance competes with food-seeking behavior. Adding a cost to the avoidance response mirrors the clinical reality of anxious individuals who avoid threatening but also possibly rewarding situations. Conversely, in the 2WAA, rodents must cross to another compartment upon a warning signal to avoid a shock, which represents a low-cost avoidance response. We hypothesized that chronic restraint stress would hinder avoidance acquisition in the 2WAA task, but increase avoidance acquisition in the PMA task. In both experiments, male and female rats underwent the chronic restraint stress protocol or remained in the control condition. In Experiment 1, all rats (N = 31) were then trained in a 2WAA acquisition and extinction procedure, in two contexts. Stressed rats showed significantly reduced avoidance acquisition, while extinction was unaffected. In Experiment 2 (N = 32), stressed rats and controls were trained in a PMA acquisition and extinction procedure. We found group and sex differences in lever pressing suppression during PMA acquisition, but not in avoidance or freezing behaviors. Both male and female rats gradually extinguished defensive behaviors during extinction. Overall, chronic restraint stress had limited effects on PMA, but significantly impacted avoidance acquisition in the 2WAA without affecting its extinction. Our findings suggest that chronic restraint stress differentially affects these two active avoidance procedures, potentially depending on how costly they are.