To determine if the complication rate of abdominal hysterectomy is increased in women with greatly enlarged myomatous uteri. Three groups of women undergoing abdominal hysterectomy were analyzed according to uterine size: group 1, 208 women with uteri less than 500 g; group 2, 63 women with uterine weights of 500–999 g; and group 3, 47 women with leiomyomata whose uteri weighed at least 1000 g. Logistic regression was used to compare the groups on the risks of having at least one major complication. Adjusted comparisons on other surgical outcomes were performed using a logistic model (for qualitative variables) or a general linear model (for quantitative variables). The risk of experiencing at least one perioperative complication, including blood loss over 500 mL, perioperative blood transfusion, major organ injury, therapeutic antibiotic use, and hospital readmission, increased significantly with uterine weight (P = .006). Group 3 women were at greater risk of having at least one of these complications than either group 1 or group 2 women, with adjusted odds ratios of 3.42 (95% confidence interval [CI] 1.62, 7.25) and 2.64 (95% CI 1.14, 6.13), respectively. Estimated blood loss with surgery also increased with increasing uterine weight (P < .001). Mean estimated blood losses for the study groups were 555.8 ± 386.5 mL (group 3), 464.3 ± 285.2 mL (group 2), and 387.6 ± 281.4 mL (group 1) (P = .032). The complication rate from hysterectomy increases with increasing uterine weight, due mainly to an increased blood loss associated with surgery for larger uteri.