In 120 adults, we measured the dominant wrist on posteroanterior roentgenograms in order to determine the normal dimensions and variations according to age and sex. Men and women were equally represented as were two age-groups (twenty-five to forty years and forty-one to sixty years). The roentgenograms were made, with standard exposure and development techniques, with the wrist and forearm in a neutral position and the x-ray tube aligned vertical to the radial styloid. The roentgenogram that was made with the wrist in the mid-coronal plane was digitized and was used to measure distances between specified landmarks. The mean ulnar variance was -0.9 millimeter (normal range, -4.2 to 2.3 millimeters). The average carpal height ratio was 53 per cent (normal range, 46 to 61 per cent). The mean radial inclination was 24 degrees (range, 19 to 29 degrees). The carpal-radial and carpal-ulnar ratios were smaller in women. The width of the distal radio-ulnar joint was reduced in the older subjects. There was a significant positive relationship (p < 0.0001) between the maximum force reached and the length of the third metacarpal. We believe that information concerning the normal roentgenographic measurements and relationship between the bones of the wrist can be used (1) to follow the progression of carpal instabilities, osteonecrosis, osteoarthrosis, or rheumatoid arthritis; (2) in clinical research; and (3) in the design of wrist implants.