To assess whether children with juvenile idiopathic arthritis (JIA) in clinical remission show pathologic findings on either gray-scale or power Doppler ultrasound of their joints. Children with JIA were eligible if they were in clinical remission for at least 3 months, as defined by the absence of clinically active joints and serologic markers of inflammation. Gray-scale as well as power Doppler ultrasonography of the wrist, knee, and ankle were carried out on previously affected joints and unaffected contralateral joints. Images were read by 2 independent readers. Findings were categorized as 1) structural abnormalities in the case of synovial thickening or increased joint fluid on gray-scale ultrasound or 2) power Doppler positive in the case of an abnormal power Doppler signal. The study cohort consisted of 28 patients. Eight of 14 patients with previous wrist involvement had pathologic gray-scale findings, and 3 of these 14 patients also had pathologic Doppler findings in the wrist. None of the 20 patients with past knee involvement had pathologic gray-scale or Doppler findings in the knee. Six of 15 patients with previous ankle involvement had pathologic gray-scale findings and 1 of the 15 patients had pathologic Doppler findings in the tibiotalar joint. This study demonstrates that some patients who meet clinical criteria for remission continue to show ongoing pathology on joint ultrasound, which may be suggestive of persistent inflammation.