During the last decade, articular ultrasonography (US) has been found effective in evaluating inflammatory, degenerative, and traumatic abnormalities of articular and periarticular tissues. In clinical practice, US used in combination with a thorough clinical evaluation can help rheumatologists to confirm or to refute diagnostic hypotheses. US is safer than computed tomography (CT), an advantage shared by magnetic resonance imaging (MRI). As compared to CT and MRI, US is less expensive; in addition, it can be performed immediately, for several joints, as often as needed. Furthermore, US allows dynamic studies. Several articles published in rheumatology journals emphasize the value of US in patients with musculoskeletal diseases. The present review article discusses the indications, efficacy, and limitations of articular US.