AIM: To determine relationships between retinal nerve fiber layer (RNFL) thickness and nadir CD4 cell count in human immunodeficiency virus (HIV) positive patients evaluated for glaucoma suspicion. METHODS: Data were reviewed for 329 HIV positive patients evaluated for glaucoma suspicion. High-definition optical coherence tomography (OCT) RNFL measurements were obtained at least 6mo apart. Analyses were performed to identify relationships between nadir CD4 count and RNFL thickness. RESULTS: Totally 110 eyes of 55 patients met inclusion criteria, of which 46 eyes were from subjects with nadir CD4<200 cells/mm3 and 64 had nadir CD4≥200 cells/mm3. Patients with nadir CD4<200 cells/mm3 had significantly thicker superior (119.7±18.6 µm) and temporal (63.8±11.7 µm) quadrants at time of initial OCT compared to the superior (112.8±16.8 µm, P=0.048) and temporal (57.1±11.9 µm, P=0.004) quadrants of patients with higher nadir CD4. This trend toward thicker RNFL among subjects with lower nadir CD4 cell counts persisted at the time of follow up OCT where participants with nadir CD4<200 cells/mm3 showed average RNFL thickness in the superior and temporal quadrants of 117.9±18.3 µm and 63.8±12.8 µm, respectively, compared to a superior thickness of 110.5±16.9 µm (P=0.034) and temporal thickness of 57.3±11.6 µm (P=0.007) among those with higher nadir CD4. CONCLUSION: Patients with lower nadir CD4 cell counts have thicker RNFL in the superior and temporal quadrants compared to those with higher nadir CD4 counts. RNFL thickness in HIV positive patients may be affected by historic HIV disease control and should be considered when evaluating HIV positive patients for glaucoma.