Longitudinally extensive transverse myelitis (LETM) is a debilitating inflammatory spinal cord lesion involving several spinal segments. There are several possible etiologies, with spinal cord sarcoidosis being a rare cause of LETM. Spinal cord sarcoidosis is, in itself, a rare manifestation of sarcoidosis that can be difficult to diagnose, especially in patients with no prior history of systemic sarcoidosis, frequently leading to a delayed diagnosis. We report the case of a 53-year-old man who developed LETM as the first manifestation of sarcoidosis. The patient presented with progressive lower limb weakness, urinary retention, sensory disturbances, and muscle spasms. Imaging studies showed hyperintense lesions extending over multiple spinal segments. After the exclusion of other causes and a lymph node biopsy showing non-caseating granulomas, the diagnosis of LETM secondary to sarcoidosis was confirmed.