Renal manifestations of syphilis are variable, with membranous nephropathy being the most commonly described lesion. Rapidly progressive glomerulonephritis (RPGN) is rare and there is only one case report in the literature describing syphilis-associated crescentic glomerulonephritis. We report a rare case of RPGN secondary to latent syphilis, which resolved with penicillin treatment in the absence of immunosuppressive therapy. A 28-year-old Black male with a history of HIV was evaluated for severe acute kidney injury, nephrotic-range proteinuria, and active urine sediment. Serologies for glomerulonephritis were negative. Rapid plasma reagin and treponema pallidum particle agglutination assay were reactive, confirming syphilis diagnosis. Kidney biopsy revealed focal and segmental necrotizing and crescentic lesion. Patient received weekly benzathine penicillin (PCN) for 3 weeks, and renal function improved to baseline. This dramatic improvement happened with PCN alone, a finding which has not been previously reported. We recommend that syphilis be considered in the differential diagnosis of all patients with proteinuria or suspected glomerulonephritis.