This three-volume set LNCS 5614-5616 constitutes the refereed proceedings of the 5th International Conference on Universal Access in Human-Computer Interaction - Addressing Diversity, UAHCI 2009, held as Part of HCI International 2009, in San Diego, CA, USA, in July 2009, jointly with 8 other thematically similar conferences. The revised papers presented were carefully reviewed and selected from numerous submissions. The papers accepted for presentation thoroughly cover the entire field of Human-Computer Interaction, addressing major advances in universal access namely interaction and support for people with sensory impairments, older users and technology interaction and support for people with cognitive impairments, design knowledge and approaches for accessibility and universal access.