Newcastle disease (ND), triggered by the Newcastle Disease Virus (NDV), is a highly infectious avian disease with substantial economic impact, affecting various bird species. This chapter reviews the current understanding of NDV, focusing on its epidemiology, pathogenesis, diagnostic methods, and control measures. NDV has caused several global outbreaks since the 1920s, with significant genetic diversity and evolving virulence among different strains. Advances in molecular diagnostics, such as RT-PCR, have enhanced the detection and differentiation of NDV strains, improving outbreak management. Despite the development of various vaccines, including live attenuated and recombinant vaccines, ND remains a persistent threat due to viral mutations and the interference of maternally derived antibodies. Effective control strategies vary globally, with developed countries employing strict biosecurity and culling measures while developing regions rely heavily on vaccination. This chapter also discusses the role of NDV’s structural proteins in its pathogenicity, the importance of early and accurate diagnosis, and the challenges faced in the implementation of vaccination programs. Strengthening global collaboration and integrating new adjuvants and vaccine delivery systems could further enhance their efficacy. By addressing these challenges and leveraging scientific advancements, sustainable control of ND can be achieved, ensuring animal health and economic stability.