In recent years, a reduction in the life expectancy gap between people living with HIV (PLWH) and the general population has been observed, irrespective of CD4 lymphocyte count, due to widespread access to antiretroviral treatment. The increase in the life expectancy of PLWH has increased awareness of both the ageing process and gender discrepancies in immune restoration and survival. Longitudinal data were collected for 2240 patients followed up at the Hospital for Infectious Diseases in Warsaw, Poland (n=1482), and the Department of Acquired Immunodeficiency, Pomeranian Medical University, Szczecin, Poland (n=758). Immune restoration was measured from the time of starting combination antiretroviral therapy until achieving 500 CD4 lymphocytes/μL, 800 CD4 lymphocytes/μL, and CD4/CD8 lymphocyte ratios of > 0.8 and > 1.0. Full recovery was achieved when the patient was restored to both 800 CD4 lymphocytes/μL and a CD4/CD8 lymphocyte ratio > 1.0. For all endpoints, immune restoration had a protective effect by reducing mortality. Patients who achieved immune restoration had a greater chance of reduced mortality than those who did not achieve immune restoration: for CD4 count > 500 cells/μL, HR=5.4 (interquartile range: 3.09-9.41), p < 0.001; for CD4 > 800 cells/μL, HR=5.37 (2.52-11.43), p < 0.001; for CD4/CD8 ratio > 0.8, HR=3.16 (1.81-5.51), p < 0.001; for CD4/CD8 ratio > 1.0, HR=2.67 (1.49-5.24), p=0.001, and for full immune recovery, HR=3.62 (1.63-8.04), p=0.002. Immune restoration remains a powerful factor in improving the survival of PLWH, regardless of the speed of recovery.