Joint contracture, a debilitating consequence of prolonged immobilization characterized by capsular fibrosis, presents a significant clinical challenge. Given the reported anti-fibrotic properties of nicorandil (NI) and extracorporeal shockwave therapy (ESW), this study investigated the potential synergistic anti-fibrotic effects of their combination on immobilization-induced knee contracture. Forty-two rats were assigned to seven equal groups: control (C), immobilization (IM), natural recovery (RM), vehicle (CMC; carboxymethylcellulose gavage), nicorandil (N; 3 mg/kg/day gavage), ESW (E; 1.5 bar, 6 Hz, 2000 pulses/session, twice weekly), and combination intervention (CI; NI + ESW). Non-control groups underwent 4-week left knee immobilization. Post-immobilization, the IM group was euthanized immediately; others underwent respective 4-week treatments. Contracture severity was quantified by range of motion (ROM) loss. Fibrosis was assessed via TGF-β1, α-SMA, and Collagen I protein expression, Masson’s trichrome staining, and α-SMA immunohistochemistry; inflammation was evaluated by H&E staining. Immobilized rats exhibited significantly (P<0.05) elevated fibrotic/inflammatory markers and ROM loss versus C, with no differences among IM, RM, and CMC groups. Both NI (N) and ESW (E) monotherapies significantly (P<0.05 vs. RM/CMC) suppressed fibrosis, inflammation, and improved ROM. Crucially, the CI group demonstrated synergistically enhanced efficacy, significantly (P<0.05 vs. N/E) reducing TGF-β1, α-SMA, Collagen I expression, inflammatory infiltration, and improving ROM beyond either treatment alone. Conclusion: Combined nicorandil and ESW therapy synergistically attenuates immobilization-induced knee contracture and fibrosis in rats by suppressing TGF-β1 signaling and extracellular matrix deposition, presenting a promising therapeutic strategy.