In a context of fast-evolving economic and urban development in Southeast Asian countries, the cities need to find sustainable mobility development paths to limit congestion and environmental issues. At the interface between individual and public transport, taxi services might have a role to play in the emergence of sustainable mobility systems. The coexistence of formal and informal sectors in mobility in Southeast Asian countries can be a fertile ground for innovations, especially since the smartphone market is on the rise. With the development of ICTs, local start-ups have emerged to offer increasingly successful ride-hailing apps. This paper explores the possibilities for ride-hailing apps to contribute to the development of innovative mobility services in Southeast Asia. It is based on two case studies, one on Kuala Lumpur (Malaysia) and the other on Ho Chi Minh City (Vietnam). Based on a wide literature review (including local media) and interviews with stakeholders, it aims to analyse the impact of ICTs on taxi services from both a user perspective and a driver perspective, and their perception by public authorities.