Introduction: Thoracic kidney is a rare form of renal ectopia caused by abnormal ascent of the kidney , often associated with diaphragmatic defects. It is usually detected incidentally during imaging performed for unrelated clinical indications. Case Report: A 6-month-old female infant, the only child of parents with hearing and speechimpairment, was admitted for evaluation of persistent tachycardia. Clinical examination revealed tachycardia without an audible murmur, signs of heart failure, or other abnormal findings. Electrocardiography and Holter monitoring confirmed sinus tachycardia. 2D echocardiography demonstrated a small atrial septal defect without hemodynamic significance. As part of further evaluation, ultrasonography of the abdomen and kidneys was performed and revealed absence of the right kidney from the renal bed, with a kidney-like structure visualized above the right hemidiaphragm. A chest radiograph demonstrated features suggestive of a posterior diaphragmatic defect with a homogeneous opacity in the right middle lobe zone. CECT of the chest subsequently confirmed an intrathoracic right kidney with herniation of segment VII of the liver through a posterior defect of the right hemidiaphragm, consistent with a diaphragmatic hernia. The left kidney was normally positioned. Anomalous systemic arterial supply to an adjacent segment of the right lower lobe raised the possibility of associated pulmonary sequestration. The child was transferred to Sirimavo Bandaranayake Specialized Children’s Hospital for further multidisciplinary management. Discussion: Thoracic kidney is a rare anomaly that may coexist with diaphragmatic and cardiopulmonary abnormalities. Early recognition facilitates appropriate imaging, parental counseling, and long-term follow-up.