Challenges posed by infectious disease outbreaks have led to a range of participatory mobile phone–based innovations that use the power of crowdsourcing for disease surveillance. However, the dynamics of participatory behavior by crowds in such interventions have yet to be examined. This article reports results from a baseline evaluation of one such intervention called Mo-Buzz, a mobile-based crowdsource-driven socially mediated system developed to address gaps in dengue surveillance and education in Colombo, Sri Lanka. We conducted a 30-minute cross-sectional field survey (N = 404) among potential users of Mo-Buzz in Colombo. We examined individual, institutional, and cultural factors that influence their potential intention-to-use Mo-Buzz and assessed if these factors varied by demographic factors. Descriptive analysis revealed high perceived ease-of-use (PEOU; M = 3.81, SD = 0.44), perceived usefulness (PU; M = 4.01, SD = 0.48), and intention-to-use (PI; M = 3.91, SD = 0.46) among participants. Analysis of variance suggested participants in the 31 to 40 years age group reported highest PEOU, whereas the oldest group reported high perceived institutional efficacy (M = 3.59, SD = 0.64) and collectivistic tendencies. Significant differences (at the p < .05 level) were also found by education and income. Regression analysis demonstrated that PU, behavioral control, institutional efficacy, and collectivism were significant predictors of PI. We concluded that despite high overall PI, future adoption and use of Mo-Buzz will be shaped by a complex mix of factors at different levels of the public health ecology. Implications of study findings from theoretical and practical perspectives related to the future adoption of mobile-based participatory systems in public health are discussed and ideas for a future research agenda presented.