OBJECTIVE. The objective of this investigation was to study the role of selective wrist arthrography of the asymptomatic wrists of patients with unilateral wrist pain and the efficacy of three-compartment and selective- compartment injections of contrast medium into the asymptomatic wrist in demonstrating symmetric and asymmetric intercarpal ligament and triangular fibrocartilage communicating defects. SUBJECTS AND METHODS. Wrist arthrography with bilateral three-compartment injections was performed for 62 patients with unilateral wrist pain. The numbers of bilateral intercarpal ligament and triangular fibrocartilage communicating defects were recorded. The results obtained with three-compartment injections in each wrist of these patients were compared with those obtained with single-compartment injections. RESULTS. Bilateral three-compartment injections identified 110 communicating defects (59 in the symptomatic and 51 in the asymptomatic wrists). Midcarpal injections showed all 36 scapholunate and lunatotriquetral ligament defects that were also shown by three-compartment injections in asymptomatic wrists. However, only 26 (72%) of these 36 ligament defects were shown by radiocarpal injections. No single-compartment injection showed all triangular fibrocartilage defects that were shown by three-compartment injections. Ten bilateral symmetric triangular fibrocartilage communicating defects were shown by three-compartment injections. All 10 triangular fibrocartilage communicating defects in asymptomatic wrists were shown by radiocarpal injections. However, only five of the 10 triangular fibrocartilage communicating defects in asymptomatic wrists were shown by injection of the distal radioulnar joints. CONCLUSION. Selective midcarpal injection of an asymptomatic wrist showed all matching detects in that wrist when only intercarpal ligament defects were found in the symptomatic wrist. Similarly, selective radiocarpal injection of an asymptomatic wrist showed all matching defects of the triangular fibrocartilage in that wrist. In either situation, routine injection of all three compartments of the asymptomatic wrist should not be necessary.