Purpose: To evaluate the impact of parathyroid gland vasculature preservation in-situ technique (PGVPIST) on postoperative parathyroid hormone (PTH) and calcium plasma levels in thyroid patients undergoing total thyroidectomy for papillary thyroid carcinoma (PTC). Study Design: Retrospective cohort study. Methods: Patients with PTC who underwent total thyroidectomy by either the conventional technique (group 1, January 2019 to January 2020) or PGVPIST (group 2, January 2020 to January 2021) were compared. Postoperative blood calcium levels and PTH levels were assessed in these groups. Results: Totally 149 patients with consecutive PTC underwent total thyroidectomy, including 60 patients in group 1 and 89 patients in group 2. Postoperative serum calcium levels in group 1 were insignificantly lower than in group 2 at day 1 (2.18 +/- 0.02 vs 2.15 +/- 0.01 mmol/L) and day 30 (2.27 +/- 0.02 vs 2.38 +/- 0.11) after surgery. But postoperative serum PTH levels in group 1 were significantly lower than that in group 2 at day 1 (23.68 +/- 2.54 vs 31.46 +/- 2.11 pg/mL) and day 30 (45.63 +/- 3.21 vs 55.65 +/- 2.89 pg/mL) after surgery. Conclusion: Parathyroid gland vasculature preservation in-situ technique for PTC is associated with higher PTH level after total thyroidectomy. The parathyroid gland vasculature mostly strongly adheres with adjacent thyroid parenchyma. Therefore, deferred processing of tiny thyroid parenchyma of parathyroid gland vessels is essential to prevent devascularization.