The present study was designed to estimate the long-term trends in the variations of wrist size and analyse the precision of models currently employed for determining the body length of adult subjects from the wrist size. Anthropometric data were obtained from 1177 subjects residing in different regions of Russia (X-ray wrist images and body length measurements). It was shown that the relative wrist size is a more stable parameter than the body length. The multiple regression models for the determination of the body length from the wrist size taking into account the subject's age or the whole stock of the available data are discussed. It is argued that the long-term variability of the relative wrist size needs to be taken into consideration for the development and application of regressive models for determining the body length.