We present a 44-year-old woman with scapular and pelvic muscle weakness, joint inflammation, and fever. Bone scintigraphy showed high uptake in proximal regions of upper and lower limbs, suspecting inflammatory myopathy and polyarticular damage. These features were the clue to request other complementary tests such as anti–aminoacyl-tRNA-synthetase antibodies and chest CT, which showed interstitial lung disease, defining an antisynthetase syndrome. Therefore, BS allows an earlier diagnosis of inflammatory muscle disease and to identify the optimal site for muscle biopsy. BS is an important step to reach a prompt diagnosis of antisynthetase syndrome for establishing an early treatment.