This study aims to examine the acceptability and feasibility of child and parent use of The Cellie Cancer Coping Kit (Cellie Kit). The Cellie kit is designed to promote coping and decrease distress in children undergoing pediatric cancer treatment. It includes a plush toy, coping cards, and book for caregivers. In study 1, 15 children (ages 6–12) undergoing cancer treatment and their parents reviewed the Cellie Kit materials and provided feedback on its acceptability and perceived feasibility of use. In study 2, 15 additional children (ages 6–12) and their parents participated in a pilot intervention of the Cellie Kit and completed follow-up interviews and a satisfaction measure. In study 1, all parents reported that they could understand the book and enact its coping tips and that the Cellie Kit was relevant to their families’ cancer experience. Children explained they would use the Cellie Kit for emotional expression, fun, and comfort. The Cellie Kit was revised after study 1 to integrate additional material suggested by families. In study 2, all families completing follow-up assessments reported utilizing the Cellie Kit. A majority (86 % of children and 100 % of parents) indicated that they would recommend the Cellie Kit to others, and most (64 % of children and 93 % of parents) reported learning new information and/or skills from the Cellie Kit. The Cellie Kit is an engaging, helpful, and easy-to-use coping tool for families facing pediatric cancer treatment. Future research should examine the efficacy of brief interventions using the Cellie Kit to promote adjustment to pediatric cancer.