Precursor B-cell lymphoblastic lymphoma (B-LBL) is a rare high-grade neoplasm of immature B cells. Most of the reported cases in the literature represent cutaneous involvement in an existing systemic precursor B-LBL or leukemia rather than primary cutaneous disease. We report a rare case of primary cutaneous precursor B-LBL in an elderly male patient who presented with swelling and ulceration of his leg. Biopsy of the skin lesion showed precursor B-LBL. Immunohistochemistry was positive for terminal deoxytransferase, CD20, CD10, CD79a, and in situ hybridization was positive for Epstein-Barr virus. To our knowledge, this is the first report that shows an association between primary cutaneous precursor B-LBL with Epstein-Barr viral infection.