Objective: This study sought to determine if dynamically tailored medication messages delivered to people living with HIV (PLWH) via text messaging would be well received and enhance adherence and clinical outcomes. Methods: A preexperimental proof-of-concept study with 52 men who have sex with men (MSM) recruited from a health clinic focused on promoting the well-being of gay, lesbian, bisexual, and transgender people. Inclusion criteria were being an English speaking HIV-positive MSM, aged 25 or older. Participants also had to agree to allow access to their medical records, have a cell phone, and be able to receive text messages over the 3-month intervention period. Participants completed baseline surveys that assessed various demographic, social, and health questions; received text messages over 3 months; answered weekly adherence questions via two-way messaging; and completed a follow-up survey at the end of the intervention period. Clinical outcomes were abstracted from participants' medical records at baseline and follow-up. Self-reported medication adherence and clinical outcomes, including CD4 counts and viral load. Results: Participants were receptive to the text messaging intervention, and reported reading and liking the messages. Self-reported medication adherence significantly improved among participants who began the study as nonadherent and received tailored medication reminders. Overall viral load significantly decreased and CD4 count significantly increased from baseline to follow-up. Conclusions: The results demonstrate that using two-way text messaging to dynamically tailor adherence messages may enhance adherence and improve important clinical outcomes for PLWH.