The aim of this study was to define the ultrasonographic factors that indicate clinical remission in patients with RA. We enrolled a cohort of patients with RA in whom the disease had been in remission for at least 6 months. Musculoskeletal ultrasound (US) examination was used to evaluate the status of active synovitis, power Doppler (PD) signalling, and synovitis in the bilateral metacarpophalangeal; proximal interphalangeal; and radiocarpal, ulnocarpal, and intercarpal, compartments of the wrist. A total of 64 RA patients with a mean disease duration of 79.97 months were studied. Of all patients, 36% had ultrasonographic synovitis and 29% an increased PD signal from at least one joint. Delay in diagnosis was highly correlated with synovitis and PD synovitis (r = 0.55, p = 0.000; and r = 0.51, p = 0.001, respectively). A weak negative correlation was evident between synovitis, PD synovitis, tenosynovitis, PD tenosynovitis, and duration of clinical remission (respectively, r = -0.426, p = 0.000; r = -0.333, p = 0.007; r = -0.243, p = 0.050; and r = -0.247, p = 0.049). Upon multivariate logistic regression analysis, the duration of clinical remission and delay in diagnosis were the factors that most influenced ultrasonographic remission (OR 3.46, p = 0.046; OR 3.27, p = 0.016, respectively). Synovial inflammation may persist in RA patients exhibiting clinical remission. We found that US detected subclinical synovitis. The most important factors preventing ultrasonographic remission were a short duration of clinical remission and delay in diagnosis.