This book constitutes the proceedings of the Third Conference on Human-Centred Software Engineering (HCSE 2010) held in Reykjavik, Iceland, in October 2010. The 10 revised full and 5 revised short papers presented were carefully reviewed and selected from 42 submissions. HCSE 2010 addresses the scientific foundations of user interface design, examining the relationship between software engineering and human-computer interaction and user-centred design as an essential part of software engineering process. Included topics focused on collaborative work; context of use; user-aware systems; model-based development; and HCI activities.