To describe the feasibility of a neuromuscular exercise (NEMEX) program in patients with mild to moderate knee osteoarthritis (KOA). Neuromuscular exercise has been increasingly used in patients with osteoarthritis to achieve sensorimotor control and improved daily function. A study of the first 23 physically active patients (11 men, 12 women; age range = 48-70 years) who had mild to moderate KOA and were undergoing an 8-week, twice-weekly program, consisting of 11 exercises with 3 to 4 levels of difficulty, as part of an ongoing randomized controlled trial. The level of difficulty was noted for each exercise and session. We recorded exertion, pain, adverse events, and adherence. For the 18 patients who participated in 6 or more sessions, a progression of at least 1 level of difficulty (out of 3-4) was observed in half or more of the exercises. However, few patients progressed to jumping activities. Exertion ranged from light to very heavy. Four patients reported a clinically relevant increase in short-term pain after 1 to 2 of the 16 scheduled sessions. No adverse musculoskeletal events were reported. Notably, 3 patients dropped out due to increased (n = 2) or persisting (n = 1) knee pain. However, their pain ratings did not show worsening symptoms. This NEMEX-KOA program was designed for physically active middle-aged patients with mild to moderate KOA; therefore, it involved exercises and difficulty levels that were more challenging than a previously described NEMEX program for patients eligible for total joint replacement. In patients with baseline mild to severe pain with activity, the NEMEX-KOA program was feasible. Progression was achieved with few incidents of clinically relevant increases in pain and no adverse events. However, jumping activities were not feasible. These findings hold promise for investigating the efficacy of the NEMEX-KOA program in individuals with mild to moderate KOA.