We evaluate an innovative grassroots community-based campaign in Seattle, WA focused on educating African American and African-born communities about concurrent partnerships and HIV transmission. Respondents completed a short self-administered questionnaire on a handheld personal digital assistant to evaluate the reach, acceptability and preliminary efficacy of the campaign. Of those who remembered seeing the campaign materials (82 %), social networks were the most common source of exposure (80 %). Respondents rated campaign materials very visually attractive (86 %), very interesting (91 %), and very important for themselves (90 %) and their community (93 %). Respondents reported that the campaign increased their knowledge about concurrency (84 %), changed their attitudes about it (77 %), and 65 % said it was likely or very likely that they would change their behavior as a result. This inexpensive grassroots campaign demonstrated extensive reach in the local black community and was able to move beyond individual exposure and into social networks.