Pneumocystis pneumonia is an increasingly recognized threat in non-HIV immunosuppressed patients and is associated with worse outcomes compared to HIV-infected patients. The preferred first line treatment is trimethoprim-sulfamethoxazole; however, second line treatments for those intolerant of this regimen have been primarily studied in patients with acquired immunodeficiency syndrome (AIDS). We report a case of Pneumocystis pneumonia in a 75-year-old man with chronic lymphocytic leukemia (CLL) and a history of sulfa allergy successfully treated with clindamycin-primaquine.