From delivering negative feedback at work to discussing death and illness with children and setting boundaries with loved ones, having difficult conversations is a necessary but challenging part of life. In this work, we introduce the Honesty-Harm Conflict (HHC) model of difficult conversations to explain how the perceived costs and benefits of difficult conversations influence honest engagement across people, contexts, and time. Building on past work, we begin with the assumption that difficult conversations are typically experienced as a tradeoff between causing immediate harm and fostering long-term learning and growth. Furthermore, communicators expect to experience personal costs during difficult conversations as a function of the immediate social harm they anticipate inflicting on others. Therefore, we propose that honest engagement in difficult conversations requires overcoming both the interpersonal challenges associated with harm aversion and the self-regulatory challenges associated with prioritizing abstract, long-term benefits over concrete, short-term costs. In the present work, we explain how these challenges influence three distinct stages of difficult conversations: establishing the truth, sharing the truth, and expressing the truth. Then, we explain when and why these challenges loom large across contexts and propose promising new interventions to overcome them. In doing so, we deepen our understanding of honesty, self-regulation, and everyday harm, and we provide practical guidance on managing, mentoring, and promoting others’ growth.