SUMMARY: Three hundred and eighty-three women whose weights were recorded during and after pregnancy were divided into groups of short (under 64 in.) and tall (64 in. and over) individuals, and further subdivided according to an index of body build (based on the observed regression of antenatal weight on height). Differences between the weight 12 months after delivery and the antenatal weight (adjusted according to the number of days by which it preceded or followed the 124th day of gestation) were examined. The proportion of short women who added weight in this interval was relatively high for those who were thinnest at the antenatal examination, was lowest for those who were moderately thin and thereafter increased with increasing degree of obesity (from about 1 in 3 to 4 in 5); the proportion of tall women who added weight showed no significant change (Fig. 2). This variation in weight change according to height is exhibited by women pregnant for the first time (Table 3). For both short and tall women, the mean weight increment of those who added weight, and the mean weight decrement of those who lost weight, increased with increasing degree of obesity (Fig. 3). When weight change is expressed as a proportion of the antenatal weight these trends disappear (Fig. 4).