Background: We present results of the development and feasibility testing of CATCH Healthy Smiles, a school-based oral health program, among children in grades K-2 in Houston, Texas. Methods: Study design was cross-sectional (N = 2 schools; N = 125 parent-child dyads; 31 kindergarteners, 42 first graders, and 52 second graders). CATCH Healthy Smiles program was implemented by trained school teachers in the 2016-2017 school year. Trained dentists conducted dental assessments to measure dental caries increment score (d3mfs). Parent-reported 24-hour dietary recalls and surveys assessed child and parent behavioral, environmental, and psychosocial factors. Logistic regression analysis assessed factors associated with caries experience adjusting for covariates. Results: Of the 113 children with complete dental assessments, 54% children in grade K, 62% in first grade, and 73% in second grade had caries experience. Children with caries experience had a higher body weight (AdjOR = 1.13, 95% confidence interval [CI]: 1.02-1.29), were less likely to be girls (AdjOR = 0.22, 95% CI: 0.05-0.82), had greater odds of difficulty drinking hot or cold beverages because of dental problems (AdjOR = 13.13, 95% CI: 1.09-275.14), greater frequency of consuming sugar-sweetened beverages (AdjOR = 11.53, 95% CI: 2.10-87.19), greater odds of receiving government assistance (AdjOR = 14.62, 95% CI: 2.74-119.81), and lower odds of seeing a dental provider (AdjOR = 0.11, 95% CI: 0.02-0.45). Process evaluation showed that 100% of the CATCH Healthy Smiles lessons and activities were taught in the two schools with a high degree of program fidelity and acceptability across the schools, children, and parents. Conclusions: These data will be used to conduct a subsequent fully powered cluster randomized controlled trial.