The aim of this research was to document the content on pro-ana blogs and to uncover how the unique socio-technical features of blogs (interactivity, self-disclosure, masspersonal communication) facilitate social support among members. A final sample of 48 pro-ana blogs provided 624 individual units for coding. Results indicate that prevalent forms of social support were emotional support, esteem support, and informational support. A new category, reciprocal self-disclosure, was also revealed to be quite frequent. Blogs are spaces where social support is sought and communicated among members of the pro-ana network. Interpretation of blog communication and implications for treatment and research are discussed.