Lues maligna, also known as malignant syphilis, is an uncommon variant of syphilis at the secondary stage – more commonly reported in immunocompromised patients or those with concomitant human immunodeficiency virus (HIV) infection. In this report, we present a case of a 28‑year‑old HIV‑negative male with a 9‑month history of multiple, well‑defined, irregularly‑shaped, erythematous papules, and small plaques evolving to ulcerated plaques and nodules with crusts, associated with pain, pruritus, and episodes of fever, arthralgia, and weight loss. Positive treponemal and nontreponemal tests, aided by histopathologic findings consistent with syphilis led to the diagnosis of lues maligna. Significant improvement of lesions was noted with 3 weekly doses of 2.4 million units of benzathine penicillin G. For patients presenting with painful and pruritic erythematous ulcerated plaques with crusts associated with systemic symptoms, and with a significant sexual history despite testing negative for HIV infection, a high index of suspicion for uncommon presentations of other sexually transmitted infections such as syphilis could aid in early diagnosis and subsequent treatment.