The aim of this study was to compare clinical evaluation of the site of hindfoot synovitis with contrast-enhanced magnetic resonance imaging (MRI) findings in children with juvenile chronic arthritis (JCA), and to evaluate the efficacy of selective guided intra-articular steroid injections. Thirteen symptomatic ankles of 11 consecutive JCA patients were examined clinically and with contrast-enhanced MRI. Pannus was demonstrated on MRI in both tibio-talar and sub-talar joints in 10 ankles, in the tibio-talar joint only in one ankle and in neither joint in two ankles. Correlation of clinical and MRI findings was good for the tibio-talar joint with concordance in 11/13 cases. Correlation was poor for the sub-talar joints. Of the 10 sub-talar joints shown to have pannus on MRI, only two were thought to have had definite clinical evidence of synovitis. Guided intra-articular steroid injection resulted in at least 6 months remission in 6/9 ankles compared with 1/10 ankles which had had previous unguided injections. We therefore recommend the use of image guidance for intra-articular triamcinolone hexacetonide injection in children with hindfoot synovitis.