Treatment of the MP joint in the patient with rheumatoid arthritis can lead to very satisfying results. Decision making is based on the degree of compromise in the hand and the knowledge of anticipated outcomes with surgery. In patients in whom pain is an overriding feature, implant surgery is highly successful. The timing for implant surgery in regard to deformity is less clear. Soft tissue correction procedures without implants appear to have value in the treatment of moderate to late disease and further documentation of the long-term outcomes will prove helpful in determining the roles of such procedures. If silicone rubber MCP arthroplasty is performed, one can anticipate an arc of motion in the 50-degree range, with improvement of extensor lag. There also is improvement of ulnar deviation, although recurrence into the 10 to 15 degree range is not unexpected. Complications such as deep infection, recurrent deformity, and implant breakage all play a role in making the decision to undertake surgery. Younger patients obviously have more risk for future prosthetic problems. The development of silicone implant arthroplasty of the MP joint has given the hand surgeon a valuable way of improving hand function in patients with severe rheumatoid involvement. It is a procedure the outcome of which may be anticipated and patients may be reassured with some degree of confidence that the hand surgeon can provide them with improved hand function.