Bilateral posterior interosseous nerve palsy in a rheumatoid patient is described. Six previous case reports and our experience indicate that steroid injection into the elbow may not produce lasting recovery and may lead to unacceptable delay before surgical decompression. An anterolateral approach for division of the arcade of Frohse is effective in cases with diffuse synovitis; where there is a local cystic swelling a posterolateral approach provides better access. Good recovery of nerve function can be expected after early operation.