We report a comparative keyword analysis of interviews and Internet postings involving people with breast and prostate cancer and discussion of sexual health. Interviewees produce retrospective accounts, their content guided by interviewers' questions, which might elicit rich biographical and contextual details. Internet exchanges concern participants' current experiences and contain detailed accounts of disease processes, medical procedures, bodily processes, and, in the case of sexual health, sexual practices. They are used by participants to exchange information and support in a relatively anonymous context. Because of the ease with which large amounts of such archived Internet materials can be accessed and analyzed, this source has considerable potential for direct observation of illness experiences, although some disadvantages also exist. This reverses an earlier situation where observational research was more laborious than qualitative interviews. Observational material for research purposes is, through the Internet, now easy to obtain and produces naturalistic data.