The Chiari network is a fenestrated embryologic remnant in the right atrium, usually asymptomatic but occasionally involved in catheter entrapment. We report a rare case where a central venous catheter guidewire became entangled in the Chiari network and required surgical removal. A 68-year-old woman scheduled for off-pump coronary artery bypass surgery (OPCAB) underwent preoperative central venous catheter placement via the right internal jugular vein. During the procedure, resistance was encountered upon withdrawal of the guidewire. Intraoperative echocardiography and fluoroscopy revealed the tip of the guidewire in the right atrium. As traction resulted in significant resistance, we proceeded with surgical removal after completion of the bypass grafting. Under cardiopulmonary bypass, the right atrium was opened, revealing fibrous strands entangling the guidewire, consistent with a Chiari network. The entangled portion was excised, and the guidewire was safely removed without damage to adjacent structures. This case highlights the importance of considering Chiari network entrapment as a differential diagnosis when encountering resistance during central venous catheter placement. Surgical intervention should be considered when percutaneous retrieval is not feasible.