Varicella-herpes zoster virus infection (VZV) is a major global health burden. This study aimed to evaluate VZV burden trends and cross-country inequalities. Age-standardized rates (ASRs) and average annual percentage changes (AAPCs) of incidence, prevalence, mortality, and disability-adjusted life years (DALYs) were analyzed. Trends were stratified by age, sex, and Sociodemographic Index (SDI). Decomposition analysis identified contributions of aging, epidemiological changes, and population growth. Cross-country inequalities were quantified through Slope Index of Inequality (SII) and Concentration Index. Globally, the ASR of DALY (ASDR) decreased from 19.3 to 12.3 per 100,000 population (AAPC: - 0.221) from 1990 to 2021, with similar declines in ASR of mortality (ASMR). While, the ASR of incidence (ASIR) increased and prevalence (ASPR) increased with AAPC of 0.161 and 0.015 respectively. The ASIR, ASPR, ASMR, and ASDR decreased until 15 - 29 years and then increased with advancing age. In 2021, high SDI regions had the greatest ASIR and ASPR, while low SDI regions had the highest ASMR and ASDR. Specially, Australia having the highest ASIR (AAPC: 2.083) and ASPR (AAPC: 0.322). Nationally, Ethiopia had the fastest ASDR decrease (AAPC: - 1.393). Decomposition analysis showed aging and population growth significantly impacted DALYs in high- and low-SDI regions. The SII of DALY decreased from - 41.57 in 1990 to - 23.88 in 2021. The concentration index of DALY decreased from - 0.38 in 1990 to - 0.34 in 2021. This study revealed significant geographical VZV burden variations, which highlights the more preventive and medical support for lower SDI populations.