<p><b>Objective:</b> This study examined the associations between anthropometric measures and uterine leiomyomas.</p> <p><b>Methods:</b> This study included a total of 5,062 women (median age of 35.5 years) who had experienced pregnancy and, of these women, 210 reported a diagnosis of uterine leiomyomas within the past 2 years prior to baseline in the Korea Nurses’ Health Study. Participants were asked about their anthropometric factors. The odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using logistic regression models.</p> <p><b>Results:</b> Mean body mass index (BMI) was 21.8 kg/m<sup>2</sup> among non-cases. An increase in weight from the age of 18 years to the present was associated with increased risk of uterine leiomyomas (<i>p</i> for trend = .002); compared to women whose weight remained stable, the multivariate ORs (95% CIs) were 1.84 (1.22–2.76) for weight gain of 5–10 kg and 2.00 (1.25–3.20) for weight gain of more than 10 kg since age 18. A similar pattern was observed when the analysis was limited to women with a BMI of 18.5–25 kg/m<sup>2</sup>. Current weight was associated with higher odds of uterine leiomyomas. No associations were found for body size in childhood or in adolescence, weight at age 18, current BMI, or current body size.</p> <p><b>Conclusions:</b> Weight gain in adulthood was associated with increased risk of uterine leiomyomas in Korean women, even in those with normal weight.</p