People strive to gain better knowledge of themselves by collecting information about their behaviors, habits, and thoughts. Personal informatics systems facilitates the collection and reflection on personal information. This workshop brought together researchers in a wide range of disciplines to discuss challenges and explore opportunities for HCI in the field of personal informatics. We identified technical and design issues. We discussed the benefits of reflecting on information about different facets of one's life, such as increased self-awareness, holistic engagement with life, and achievement of life balance. Key research areas include: ubiquitous computing, life logging, visualizations, persuasive technologies, interaction design, and the psychology of self-knowledge and self-awareness.