Tenosynovitis is common in rheumatoid arthritis (RA) but knowledge is limited regarding its response to anti-inflammatory treatment. This study used ultrasonography (US) to examine the distribution and responsiveness of tenosynovitis to anti-tumour necrosis factor (anti-TNF) treatment in RA patients. Twenty patients with RA were examined at baseline and 1, 3, 6, and 12 months after starting adalimumab treatment, and grey-scale (GS) and power Doppler (PD) US scoring (semi-quantitative range 0-3) of wrist and ankle tendons was performed in addition to assessment of the 28-joint Disease Activity Score (DAS28), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR). The extensor carpi ulnaris (ECU) tendon in the wrists and the closely related tendons tibialis posterior (TB) and flexor digitorum longus (FDL) in the ankles were most often inflamed. Median sum scores for this reduced number of tendons at baseline/12-month follow-up were 5/0.5 for GS (p < 0.001) and 4/0 for PD (p < 0.05), with reductions in the US scores during follow-up as large as those found for sum scores of all tendons. The standardized response means (SRMs) for sum GS or PD scores of the reduced number of tendons were higher (range -0.53 to -0.93) than for the sum scores of all tendons (-0.23 to -0.74), and showed larger responsiveness than CRP (-0.10 to -0.43) and ESR (-0.03 to -0.71). Bilateral assessments of ECU, TB, and FDL tendons were as sensitive to change as the sum scores of all tendons, and scoring of this reduced number of tendons is suggested to be included in US scorings for follow-up of RA patients.