Spontaneous or traumatic bleeding is a common complication of systemic thrombolysis in patients with acute ischemic stroke. We report the case of an 83 y.o. woman with right facio-brachio-crural hemiparesis, left deviation of the head and aphasia who developed, after thrombolytic therapy, a spontaneous sternocleidomastoid muscle hematoma that regressed few days later. To our knowledge, this is the first case reported in the literature of asymptomatic and spontaneous skeletal muscle hematoma following thrombolysis for the treatment of acute ischemic stroke. The occurrence of lateral cervical tuberculosis lymphadenitis ipsilateral to sternocleidomastoid muscle hematoma may suggest a causal relationship between local chronic inflammation of active mycobacterial infection and thrombolysis-related extravasation. This case should suggest caution in thrombolytic treatment in patients with chronic immune dysregulation and vascular inflammation such as extra-pulmonary tuberculosis.