<p>This study aimed to examine recent trends and educational inequality in smoking prevalence among Vietnamese adults between 2020 and 2024, providing evidence to inform targeted tobacco control interventions. Data were obtained from three rounds of the Provincial Global Adult Tobacco Surveys (PGATS) conducted in Vietnam (2020, 2022–2023, and 2024), involving nationwide samples totaling 69,776, 61,763, and 74,962 participants aged 25 or older, respectively. Current smoking and daily smoking rates were estimated. Absolute (Slope Index of Inequality, SII) and relative inequalities (Relative Index of Inequality, RII) of current smoking and daily smoking were analyzed using the Poisson regression-based method in regard of educational level. Overall smoking prevalence among those aged 25 and older declined from 24.4% in 2020 to 20.8% in 2024, with the male smoking rate of 47.3% and 41.1%, respectively. Daily smoking showed a similar trend (19.8% in 2020 to 16.6% in 2024). The smoking prevalence among men was consistently higher than among women, and rural residents, married individuals, and lower educational groups exhibited higher smoking rates across all years. The substantial educational inequalities persisted. Absolute inequalities slightly decreased for current smoking (SII: 18.5% in 2020 to 14.3% in 2024) and daily smoking (SII: 18.1–15.0%), yet relative inequalities remained stable (RII from 0.47 to 0.51 for current smoking; approximately 0.40 for daily smoking). While Vietnam has experienced a moderate decline in smoking prevalence, significant educational inequalities persist. To effectively address tobacco-related disparities, targeted interventions focusing on socioeconomically disadvantaged groups are necessary, underscoring the need for equity-oriented tobacco control policies.</p>