To investigate HIV-1-related B cell disorders, the quantity of CD27 positive (CD27⁺) B cells and their CD38, CD95, and bcl-2 intensities were examined by flow cytometry analysis in 16 drug-naive patients, 27 highly active antiretroviral therapy (HAART)-treated patients, and 20 uninfected controls. CD27⁺ B cells have been recognized as memory B cells. The mean percentage of CD27⁺ B cells was significantly lower in drug-naive patients (11.9%) and in HAART-treated patients (16.1%) than in controls (31.4%) (p < 0.01). The intensities of CD38 and CD95 on CD27⁺ B cells were higher in drug-naive patients than in controls (p < 0.01 in CD95). The intensity of CD95 on CD27⁺ B cells in HAART-treated patients was lower than that of drug-naive patients, but significantly higher than that of controls (p < 0.01). The intensity of bcl-2 on CD27⁺ B cells was equivalent among the three groups. These findings suggest that disturbance of peripheral B cell composition, exemplified by CD27⁺ B cell reduction, exists in both drug-naive and HAART-treated HIV-1-infected patients. In addition, the augmented apoptotic state of CD27⁺ B cells found in HAART-treated patients with undetectable viral loads, indicated by CD95 elevation, suggests that some HIV-1-related B cell disorders last for years after effective antiviral therapy.