A plant-based dietary pattern has been recommended for its potential health and environmental benefits, but its relation to mortality warrants further exploration1. We examined this association among 13,154 adults aged 65 years and older (57.4% female) in the Chinese Longitudinal Healthy Longevity Survey (CLHLS). The overall plant-based diet index (PDI), healthful plant-based diet index (hPDI) and unhealthful plant-based diet index (uPDI) were calculated using dietary data collected by a simplified food frequency questionnaire (FFQ). Compared with the lowest quintile, participants in the highest quintile of PDI and hPDI had a decreased risk of all-cause mortality (hazard ratio (HR) = 0.92; 95% confidence interval (CI) 0.86, 0.98 for PDI; HR = 0.81, 95% CI, 0.76, 0.87 for hPDI), whereas participants with the highest uPDI scores had a 17% (95% CI, 9%, 26%) increased risk. Among plant foods, fresh fruits, fresh vegetables, legumes, garlic, nuts and tea were the main protective contributors, whereas preserved vegetables and sugar were associated with a higher risk of mortality. These findings support the beneficial roles of overall and healthful plant-based dietary patterns. The quality, and not only quantity, of plant foods should be emphasized in relevant public health recommendations.