Workplace bullying has been a serious workplace concern for centuries, with individuals confronting various forms of abuse, mistreatment and bullying at work. Historical accounts indicate that the powerful Egyptian pharaohs strategically lured tribal people to work at their construction sites, which led to submission, slavery and bullying. Regardless of the era, the enduring nature of bullying issues illustrates that individuals can misuse their power by using bullying to establish control and authority over other individuals. In contemporary environments such as New Zealand (NZ) healthcare organisations, workplace bullying remains a significant threat that exposes healthcare workers, including junior doctors, to health and safety issues. Despite literature documenting the prevalence and harmful impacts of bullying on NZ junior doctors, there is a lack of theoretical explanations behind bullying in this context. This notable gap in understanding the explanations of bullying impedes effective prevention and management of workplace bullying among NZ junior doctors. The research aimed to explain the bullying process among NZ junior doctors with the objective of facilitating prevention and management. Twenty doctors (n=20) from various specialities in medicine and surgery participated in in-depth interviews. Data collection and analysis were guided by the Constructivist Grounded Theory (CGT) approach. Seven core categories resulted from the data analysis. Six provided explanations of bullying, highlighting the complex interplay of many factors, including social and individual characteristics of the bullies and victims, team dynamics, hierarchy, organisational culture, systemic factors, and acceptance culture. The seventh core category described the prevention and management of bullying. CGT analysis of the data led to the development of Acceptance Culture Theory (ACT), which is the contribution of this study. ACT outlines the social process of acceptance of bullying at multiple levels of individuals’ ecological systems. An acceptance of bullying at the micro level caused individuals to endure and accept bullying, with effects seen at multiple levels (micro, meso, exo and macro) that perpetuated an acceptance culture of bullying in the individuals’ work environments, keeping them trapped in a cycle of bullying. Effective prevention and management are possible by breaking the acceptance culture using comprehensive approaches encompassing macro, meso, exo, and micro levels. Alleviating hierarchal structures, frequent changes in leadership, organisational support, changes in policies and procedures, and a robust reporting system are critical for the effective prevention and management of bullying. By addressing the root causes of workplace bullying, a safe and healthy workplace can be offered for NZ junior doctors.