Background <p>Mastoidectomy procedure is essential for eliminating chronic otitis media (COM) resulting from cholesteatoma. Iatrogenic facial nerve injury following mastoidectomy operation is mostly expected due to intraoperative injury to the course of the facial nerve within the temporal bone whether to the tympanic segment, second genu or the mastoid segment resulting in lower motor neuron (LMN) palsy. On the other hand, Upper motor neuron (UMN) facial palsy can occur postoperatively in neurosurgical and cardiovascular surgeries. Also, severe intraoperative hypotension or hypertension can be a cause.</p> Case presentation <p>Here, we present an unusual case of upper motor neuron facial nerve injury following mastoidectomy due to middle cerebral artery (MCA) infarction which occurred intraoperatively and caused clinically evident facial nerve affection on the same side of the operation. Thus, such condition proposed a special diagnostic challenge.</p> Conclusions <p>This unusual presentation highlights the importance of documenting the facial nerve assessment intraoperatively and thorough physical and neurological assessment postoperatively to determine the exact aetiology of facial nerve palsy following mastoidectomy.</p>