Study Design Secondary analysis of clinical trial data. Background Knee osteoarthritis (OA) management has changed significantly over recent decades toward nonpharmacological treatments, particularly exercise. However, the optimal exercise program remains to be established. Objective To describe the implementation of standardized rescue exercises for patients with pain exacerbations and to assess whether performing these benefit or further worsen symptoms in patients with exacerbated symptoms of knee OA. Methods The data from 2 randomized controlled studies of exercise in patients with knee OA were used. A supervised, standard exercise program that included standardized "rescue" exercises to be performed in the event of symptomatic exacerbation, defined as knee pain of greater than 5 on a 0-to-10 numeric pain-rating scale, was conducted for 12 weeks at 3 sessions per week. Pain ratings were obtained before and after each exercise session. Results Of 131 participants included, 2 never commenced the exercise program, leaving 129 to be included in the analysis. The analysis was observational and thus had no comparison group. During the program, 36 participants (28%) were referred to the rescue exercises. In 63% of the rescue sessions, the participants experienced decreased pain intensity (average ± SD, -2.6 ± 2.3), 27% reported no change in pain, and 10% reported increased pain intensity (average ± SD, 1.3 ± 0.5). Conclusion Having a predefined and standardized rescue exercise option appears beneficial, and did not result in further worsening of exacerbated knee OA symptoms. The intervention may be particularly relevant for patients with knee OA who have more severe symptoms. Level of Evidence Therapy, level 2b. Registered at www.clinicaltrials.gov (NCT01545258 and NCT01945749). J Orthop Sports Phys Ther 2016;46(11):942-946. Epub 28 Sep 2016. doi:10.2519/jospt.2016.6908.