Vasopressin is a peptide hormone produced by the hypothalamus and stored in the posterior pituitary. It is secreted in response to hypotension and hyperosmolarity. Vasopressin and its analogs have been widely used in vasodilatory shocks such as septic shock and cardiogenic shock. The sudden withdrawal of vasopressin after its prolonged use can lead to polyuria and rising sodium levels, which is concerning for the diagnosis of diabetic insipidus (DI); likely central rather than nephrogenic in origin. We present a case of diabetic insipidus following the sudden discontinuation of a prolonged vasopressin infusion for septic shock, which responded to tapering doses of desmopressin.