Background <p>Dysglycemia is common in acromegaly and may improve after transsphenoidal surgery, but factors associated with early postoperative glycemic improvement are unclear. We aimed to identify perioperative factors associated with glycemic improvement at first follow-up, focusing on preoperative HbA1c and postoperative day 1 fasting plasma glucose (POD1 FPG).</p> Methods <p>This retrospective cohort study included 175 acromegaly patients with preoperative dysglycemia who underwent transsphenoidal surgery (2019–2024). The primary outcome was early glycemic improvement (normalization or downgrading from diabetes to prediabetes) at ~ 1 month post-surgery. Logistic regression and restricted cubic spline analyses were performed.</p> Results <p>Glycemic improvement occurred in 84 patients (48.0%). Higher preoperative HbA1c (OR 0.60, 95% CI 0.42–0.85, <i>P</i> = 0.005) and higher POD1 FPG (OR 0.67, 95% CI 0.50–0.89, <i>P</i> = 0.007) were independently associated with lower odds of improvement. Improvement rates decreased across HbA1c tertiles (69.5%, 39.7%, 34.5%; P for trend &lt; 0.001). Patients with POD1 FPG in the optimal range (5.5-7.0 mmol/L) had higher improvement rates than those outside this range (61.9% vs. 35.2%; adjusted OR 0.38, 95% CI 0.20–0.74, <i>P</i> = 0.004).</p> Conclusions <p>In acromegaly patients with preoperative dysglycemia, both preoperative HbA1c and POD1 FPG were independently associated with early postoperative glycemic improvement. These glycemic markers may improve short-term risk stratification beyond broad preoperative glycemic categories.</p> Clinical trial number <p>Not applicable.</p>