Nesfatin-1 was identified as a satiety factor involved in the regulation of metabolism. Altered levels of circulating nesfatin-1 had been observed in a variety of diseases characterized by energy imbalance. However, there was no published data about nesfatin-1 levels in acromegaly.We evaluated serum nesfatin-1 levels in 13 patients with acromegaly at baseline and postoperatively, and in 21 age- and body mass index (BMI)-matched healthy subjects.Compared with the healthy subjects, patients with acromegaly had significantly increased levels of serum insulin, high-density lipoprotein cholesterol, triglyceride, and growth hormone (GH). Moreover, the acromegaly group had nesfatin-1 levels higher than controls (1.96 ± 0.56 ng/mL vs 0.61 ± 0.10 ng/mL, P = .004). There was a positive correlation of serum nesfatin-1 levels with diastolic blood pressure (r = 0.579, P = .038) and homeostasis model assessment of insulin resistance (HOMA-IR) (r = 0.598, P = .031) in patients with acromegaly. While a successful surgery decreased serum GH levels, the serum nesfatin-1 levels did not change in acromegaly (P = .965). At last, we compared serum GH/nesfatin-1 levels with predictive markers for aggressive behaviors in pituitary adenomas. There was no relationship between serum nesfatin-1 levels and tumor's size, Ki-67 index, mutant p53, or MGMT proteins. However, increased serum GH levels were positively correlated with tumors' size (P = .023) and mutant p53 proteins expression (P = .028).Circulating nesfatin-1 was increased in acromegaly, which was involved in metabolism regulation.