More than half of Latino adults living in the USA are expected to develop type 2 diabetes in their lifetime. Despite the growing interest in smartphone use for weight loss and diabetes prevention, relatively few clinical trials have evaluated the efficacy of mobile app-based interventions in Latino populations. The aim of this study was to evaluate the potential efficacy of an in-person weight loss intervention in conjunction with a commercially available Fitbit app in a Latino sample at risk for type 2 diabetes and explore significant predictors associated with weight loss. After the run-in period, 54 self-identified Latinos with body mass index (BMI) > 24.9 kg/m2 were enrolled in an 8-week uncontrolled pilot study, and received a Fitbit Zip, its app, and two in-person weight loss sessions adapted from the Diabetes Prevention Program. Mean age was 45.3 (SD ± 10.8) years, 61.1% were born in the USA, and mean BMI was 31.4 (SD ± 4.1) kg/m2. Participants lost an average of 3.3 (SD ± 3.4) % of their body weight (p < .0005). We also observed statistically significant reductions in hip and waist circumferences, and systolic and diastolic blood pressure (p < .001). After controlling for demographic factors, use of the mobile app weight diary at least twice a week (p = .01) and change in the International Physical Activity Questionnaire score (p = .03) were associated with change in percent body weight. The intervention showed the potential efficacy of this intervention, which should be formally evaluated in a randomized controlled trial.