Difficult discussions with patients and families are a primary component of pediatric oncology care. We report our experience in the development and implementation of a longitudinal simulation-based Communication Skills Curriculum within a pediatric hematology-oncology fellowship training program. A 6-session simulation curriculum was created for fellows to practice difficult oncology related discussions with a standardized patient (SP). This program was implemented in 2017 and continues presently. Throughout fellowship training the scenarios progress in content and scope. Each simulation was observed and recorded, and written and verbal feedback was provided. The Gap-Kalamazoo Communication Skills Assessment Form was used to assess communication skills in each session. A total of 15 fellows (100% of possible participants) have participated in this curriculum to date. Across all domains of communication skills assessed, the ratings given by the physician evaluators and self-evaluations improved over the course of the scenarios completed throughout fellowship training. This type of simulation-based communication skills curriculum within a pediatric hematology-oncology fellowship training program is feasible to implement. This training is useful to fellows beyond training in improving communication skills, which has the potential to directly benefit the future patients they care for.