The opening of the Lao–China railway in December 2021 has reshaped the accessibility of northern Laos, bringing large numbers of domestic and regional visitors to destinations that were previously reached only by road. This study examines how the railway has changed community-based ecotourism and youth employment in four villages in Luang Prabang and Vang Vieng, two of the destinations most directly affected by the new line. A mixed-methods design combined a household survey of 312 residents aged 18 to 35, key informant interviews with 26 village leaders, enterprise owners and tourism officials, and analysis of visitor records held by village tourism committees and district offices. The findings show a substantial rise in visitor numbers, with arrivals at the four villages increasing by between 62 and 148 per cent over the three years following the railway's opening, and a corresponding increase in youth participation in tourism-related work. However, local value capture remains limited. Most additional revenue accrues to tour operators, transport providers and accommodation businesses based in provincial towns, while village enterprises capture a small share of visitor spending and youth employment is concentrated in low-wage, seasonal and informal roles. Villages with functioning tourism committees, product diversification and access to enterprise support recorded higher local income shares. The paper concludes that infrastructure-led tourism growth does not automatically translate into community benefit and argues that targeted enterprise support, skills development and stronger contractual arrangements with operators are required if the railway is to deliver inclusive rural development.