In this observational study, influences on research enrollment were examined in the context of an educational research study. Recruitment materials were sent to parents of kinder-gartners in one of 23 classes across 7 public schools, as an invitation to enroll in a longitudinal study. For the 7 classes from 2 of the schools, the school principal prepared a cover letter as an introduction to the educational study. Inclusion of this cover letter was associated with a significantly swifter pace of recruitment and, to a lesser degree, with an increase in the number of children enrolled. However, when potential confounding variables were controlled, no significant increase in final enrollment count was associated with including the cover letter. Thus, inclusion of a cover letter from the school principal did not appear to dramatically increase the number of parents who elected to enroll their child in the educational study, and it did significantly decrease (by 6 weeks) the number of weeks required to achieve final enrollment counts.