Objective: The objective of this case series is to highlight the workup of adrenal insufficiency as cause of hypoglycaemia with recurrent seizures. Case series: We report 4 cases of IAD presenting at 5-month, 27-month, 4 month and 6 months of age with lethargy, hypoglycaemia and recurrent seizures. All patients had documented cortisol deficiency and TBX-19 mutation. All were treated with oral steroids along with resolution of symptoms and catch-up growth. Conclusion: IAD Isolated ACTH deficiency (IAD) is a rare cause of adrenocortical insufficiency, characterized by low ACTH and cortisol levels, which causes early and severe secondary adrenal insufficiency without other pituitary defects. High suspicion with genetic diagnosis with timely treatment with steroids is the key to improve morbidity and mortality.