The study was to describe sonography findings of ankle joints in gout patients and compare detection abilities of signs of gout in ankle joints among sonography, clinical characteristics and conventional X-ray. In acute gout, a double contour sign was seen in 46.3 percent, effusions in 40 percent and synovial hypertrophy on ultrasonography was 32.5 percent. In chronic gout, tophaceous material was seen in 48.3 percent, erosions adjacent to tophaceous material were seen in 26.7 percent. The double contour sign was significant and seen not relying on disease duration. Sonography was superior to radiograph in evaluating tophaceous material (p 0.05). However, radiograph was more sensitive in the detection of bone erosions (p 0.05). In conclusion, sonography can detect deposition of MSU crystals and evidences of synovitis in acute gout which X ray can not detect.