OBJECTIVES: For patients with pituitary adenomas with an intact hypothalamus-pituitary-adrenal axis before surgery, whether routine steroid therapy is needed is still controversial. We conducted a meta-analysis to assess the safety of withholding hydrocortisone compared with hydrocortisone in pituitary adenoma patients during preoperative periods. MATERIAL AND METHODS: We searched PubMed, Embase, Web of Science, and Cochrane Library databases up to November 2022 using inclusion and exclusion criteria. We employed either a fixed-effect or random-effect model for the analysis and assessed heterogeneity using the I2 statistic. RESULTS: Three studies involving 512 patients out of 400 studies were conducted. The pooled data revealed a higher incidence of postoperative transient diabetes insipidus in the no-hydrocortisone group than in the hydrocortisone group (RR, 1.88; 95% CI, 1.13 to 3.12; p = 0.02). The cortisol level in the no-hydrocortisone group was lower than in the hydrocortisone group after tumor removal (mean difference, -36.82; 95% CI, -44.27 to -29.38; p < 0.00001) but higher on the second day after surgery (mean difference, 4.04; 95% CI, 2.38 to 5.71; p < 0.00001). No significant differences were observed in early adrenal insufficiency (RR, 1.04; 95% CI, 0.37 to 2.96; p = 0.93), adrenal insufficiency in the third month after surgery (RR, 1.56; 95% CI, 0.70 to 3.48; p = 0.28), cortisol level on the first day after surgery (mean difference, 0.24; 95% CI, -11.25 to 11.73; p = 0.97), postoperative permanent diabetes insipidus (RR, 1.61; 95% CI, 0.43 to 6.07; p = 0.48), postoperative delayed hyponatremia (RR, 1.06; 95% CI, 0.41 to 2.74; p = 0.91), or postoperative blood glucose level (mean difference, -0.41; 95% CI, -1.19 to 0.37; p = 0.31) between the no-hydrocortisone and hydrocortisone groups. CONCLUSION: Withholding preoperative steroid therapy is safe for pituitary adenomas patients with an intact hypothalamus-pituitary-adrenal axis.