Background <p>Afterschool programs and mentoring programs are two widely implemented approaches to promoting youth development. Such interventions vary widely in design and evidence regarding program success; increasing understandings of the structure and implementation of such programs is essential to informing future efforts.</p> Objective <p>Through an examination of program facilitator perspectives, the current study explores the implementation and perceived benefits and challenges of a nine-week afterschool mentoring program that aims to ease the high school transition for seventh grade students.</p> Methods <p>Data were collected using pretest and posttest self-report surveys administered to program facilitators between Fall 2017 and Spring 2019, with 156 respondents completing pretest surveys and 73 providing matched post-test surveys. Descriptive statistics and reflexive thematic analysis were used to interpret the data.</p> Results <p>Results indicate that volunteers regularly prepared for weekly sessions, but time constraints led to excluded curriculum content each week. Quantitative ratings of youth engagement and collaborative behaviors, as well as program impact measures such as self-esteem, were at least moderately high. Qualitative analyses offered insights on issues with youth engagement during group discussions and program activities, gender-specific challenges, and the potential impacts that uninvested facilitators, environmental design, and large groups of students can have on program implementation and effectiveness.</p> Conclusions <p>Results are discussed in reference to existing literature and seven recommendations with respect to the implementation of afterschool mentoring programs are presented. These insights relate to the group mentorship model, physical environment of the program, module focus, and curriculum design.</p>