Background <p>Thalamoperforating artery (TPA) pseudoaneurysms are relatively uncommon and often pose significant challenges in detection through vascular examination. Furthermore, their management, particularly via endovascular therapy, is complex and demanding. This article presents a case study of a patient diagnosed with an acute TPA pseudoaneurysm, highlighting its rarity and the intricacies involved in its treatment.</p> Case presentation <p>A 49-year-old male was admitted to our hospital presentingwith headache and vomiting, with a medical history notable for hypertension and previous cardiac surgery. Neurological examination was remarkable solely for neck stiffness. Initially, imaging revealed an aneurysm of the left internal carotid artery (ICA) concurrent with the first episode of subarachnoid hemorrhage, with no other aneurysms detected. On the third day post-embolization of the left ICA aneurysm, recurrent subarachnoid hemorrhag prompted emergency angiography, which identified a new pseudoaneurysm of the TPA. Subsequent endovascular treatment with electrocoagulation resulted in a favorable recovery, and there has been no recurrnce of the aneurysm.</p> Conclusions <p>TPA pseudoaneurysm is an exceedingly rare condition that often eludes detection during initial vascular imaging via angiography, necessitating repeated angiographic examinations. The management of TPA pseudoaneurysm presents significant. challenges due to its rarity. Notably, the application of electrocoagulation as a treatment modality for TPA pseudoaneurysm has not been documented in existing literature. Electrocoagulation may serve as a viable alternative when microcatheter navigation into the aneurysm is not feasible. however, attention must be given to its potential limitations. The long-term efficacy and durability of this technique warrant careful monitoring through ongoing follow-up.</p>