To develop mobile-based physical activity promotion text messages, understand users' preferences, and assess feasibility and acceptability in a college student sample. Five focus groups (N = 33) were conducted using a participatory approach. An Audience Response System was adopted for data collection to ensure confidentiality and for directing the discussion foci. A framework analysis of transcribed focus group discussions was conducted. Atlas. ti qualitative analysis software was used to manage the data. Participants were uniformly enthusiastic about a text message-based intervention to encourage regular physical activity. They also preferred positive, supportive personally tailored messages. Participants placed a high value on messages related to establishing and monitoring realistic and achievable goals. mHealth text messaging was well received. The results support the feasibility and acceptance of such an intervention.