Toxoplasma gondii infection is a prominent cause of morbidity and mortality in patients with human immunodeficiency virus (HIV) infection in the post-highly active antiretroviral therapy era, particularly in those who are seronegative, recently diagnosed of having HIV, or in poor or underserved areas. We present a case of fatal disseminated toxoplasmosis with Toxoplasma encephalitis in a 16-year-old boy with a high HIV viral titer who had a negative enzyme-linked immunosorbent assay and Western blot result on initial presentation. His first clinical manifestation of underlying disease was renal insufficiency, which was found on biopsy to be due to focal segmental and global collapsing glomerulopathy, a variant of focal segmental glomerulosclerosis. Collapsing glomerulopathy is a disease commonly associated with and histologically identical to HIV-associated nephropathy. Delay in the diagnosis of HIV and lack of appropriate antiretroviral therapy and Toxoplasma prophylaxis eventually led to his death 7 months later. This case reaffirms the importance of an awareness of HIV-related diseases, such as collapsing glomerulopathy, which could help in the early diagnosis of HIV, and the importance of proper and prompt antiretroviral and T. gondii antimicrobial therapy in patients with HIV infection.