Soil-transmitted helminth (STH) infections remain a significant public health concern in endemic regions. This study aimed to determine the prevalence, infection intensity and distribution of STH infections across age groups and ecological settings in southern and Central Highlands Vietnam. A cross-sectional survey was conducted among 1241 individuals in four provinces. Faecal samples were examined using the Kato-Katz technique, and infection intensity was classified according to WHO criteria. Differences in prevalence among provinces and age groups were analyzed using Chi-square and Fisher's exact tests. The overall prevalence of STH infections was 7.2% (89/1241). Hookworms were the predominant species (6.9%), followed by Trichuris trichiura (0.3%), while Ascaris lumbricoides was not detected. Lam Dong Province showed a significantly higher prevalence (12.7%) compared to Tay Ninh (7.9%), Binh Duong (5.4%), and Ba Ria-Vung Tau (0.8%) (P < 0.001). Single infections accounted for 7.1% of cases, whereas co-infections were rare (0.08%). The highest prevalence was observed among adults aged 19- 65 years (9.5%) (Fisher's exact test, P < 0.001). Working-age adults may serve as an important reservoir of infection, particularly for hookworm, highlighting the need to consider adult populations in future surveillance and control strategies.