Posteroanterior radiographs of normal wrist were taken in seventeen volunteers, and analysed to determine the dynamic relationships between the radiocarpal and midcarpal joint during radioulnar deviation. The total arc of radioulnar deviation was 59 degrees, and the motion was 44% radiocarpal and 56% midcarpal. During radioulnar deviation, the motion at the midcarpal joint was more than that at the radiocarpal joint. It is suggested thst dorsoradial and palmar-ulnar flexion as it occurs at the midcarpal joint can be correlated in radio-ulnar deviation of the wrist more than the coronal sliding motions as it occurs mainly at the radiocarpal joint.