Objectives: The objective of this study was to assess knowledge, attitudes, and behaviors surrounding healthcare-related mobile phone use and text messaging among persons at risk for or infected with tuberculosis (TB) or the human immunodeficiency virus (HIV). Methods: An anonymous survey was conducted in three groups of subjects: (1) HIV-infected persons attending an HIV clinic; (2) persons with latent TB infection at a public health clinic; and (3) persons presenting for TB, HIV, and syphilis screening at a community screening site. Results: Three hundred fifteen (n = 315) persons responded to the survey, of whom 241 (76.5%) owned a cell phone. Cell phone owners were younger and more educated than nonowners. Transportation difficulty and forgetting appointments were cited as significant barriers by 34.2% and 39.5% of respondents, respectively. Fifty-six percent of subjects felt it would be acceptable to receive text message appointment reminders, and 33% felt that text message reminders to take medications would be acceptable. Younger age and cell phone ownership were significantly associated with acceptance of text message reminders. Black and Hispanic subjects were more likely to feel that text message reminders for appointments or medications were helpful than White subjects. Further, Black and Hispanic subjects, as well as subjects with lower educational attainment, were more receptive to healthcare-related educational text messages. Conclusions: Cell phones and text messaging were prevalent among our subjects attending HIV and TB clinics, and subjects were generally receptive to text messaging for healthcare-related communication. Interventions that explore the potential for text messaging to improve clinic attendance, medication adherence, and health knowledge should be explored.