Central diabetes insipidus or vasopressin deficiency (AVP-D) is the most frequent water balance disorder after transsphenoidal surgery (TSS) with variable prevalence amongst studies. We aimed to determine rates of newly-developed transient or permanent AVP-D in patients with pituitary tumours treated with TSS. We performed systematic review of Medline, Embase and Cochrane Library between 01/01/2000-31/01/2021 for studies reporting on outcomes for pituitary adenoma, craniopharyngioma and Rathke's cleft cyst (RCC) after TSS and providing definition of post-operative AVP-D. We pooled the results as proportions with 95% confidence intervals (CIs) using Freeman-Tukey transformation random effects meta-analysis. From 11694 studies, 51 were included. Rates of transient or permanent AVP-D were: 17% (95% CI, 13-21) and 3% (95% CI, 2-5) in total group, 16% (95% CI, 12-21) and 2% (95% CI, 2-3) in pituitary adenomas, 31% (95% CI, 24-39) and 30% (95% CI, 22-39) in craniopharyngiomas, 35% (95% CI, 16-57) and 14% (95% CI, 6-23) in RCCs, respectively. Based on diagnostic criteria, rates of transient or permanent AVP-D were: for hypotonic polyuria, 14% (95% CI, 8-22) and 3% (95% CI, 1-4), for hypotonic polyuria and hypernatraemia, 21% (95% CI, 13-29) and 5% (95% CI, 2-11), for desmopressin administration, 22% (95% CI, 15-29) and 9% (95% CI, 0-30), respectively. Following TSS, a small proportion of patients with pituitary adenoma have permanent AVP-D (2%), but prevalence reaches 30% in ones with craniopharyngioma and 14% in those with RCC. Diagnostic criteria for post-operative AVP-D remain variable affecting reported rates of this condition.