Student views of treatment acceptability of an intervention is important but still is neither regularly assessed nor studied beyond non-behavioral interventions. Furthermore, assessment of treatment acceptability across time is almost never considered. Using data from a longitudinal, randomized controlled trial, we examined variables that predicted students' treatment acceptability of Check & Connect, a mentoring intervention with promise for promoting school engagement. A series of multiple regressions with multiple imputations revealed that students' treatment acceptability ratings in Year 1 significantly predicted Year 2 ratings. Other variables examined, including dosage, change in mentor, and student and mentor characteristics, were not significant in predicting students' treatment acceptability ratings in Year 2. Implications for using treatment acceptability to facilitate buy-in and further replications are discussed.