Despite an increasing use of formal healthcare systems such as the Electronic Medical Record (EMR) and communication devices, informal communication continues to play an important role in the highly collaborative, dynamic, and information-rich medical work. Formal systems often fail to support the spontaneous and opportunistic needs of healthcare providers to communicate patient information. Yet it is not clear what constitutes informal communication in healthcare practices, what roles does it play in the patient care process, what types of technologies can be designed to support informal communication, and how to design them. This workshop aims to gather interested researchers to better understand informal communication in healthcare, to discuss their implications for CSCW healthcare research, and to brainstorm technological innovations that can support the informal aspects of health communication.