Asphalt mixture design is a critical process in pavement engineering that involves selecting and proportioning aggregates and asphalt binder to produce durable, high-performing hot mix asphalt (HMA). This chapter explores the fundamental principles underlying asphalt mixture behavior under various loading and environmental conditions, emphasizing the balance between structural strength, flexibility, and resistance to deformation and cracking. A comprehensive overview of the major mix design methodologies is provided, including the Hubbard-Field, Hveem, and Marshall methods. Each method is examined in terms of testing procedures, equipment, performance indicators, and applicability. Special emphasis is placed on the Marshall method, covering specimen preparation, compaction, stability and flow testing, and key volumetric parameters such as air voids, voids in mineral aggregate (VMA), and voids filled with asphalt (VFA). The chapter also addresses the challenges of replicating field conditions in laboratory settings and outlines methods for simulating short- and long-term aging. Additionally, it provides practical guidance on aggregate batching, temperature control, and conditioning procedures. Analytical approaches for determining optimum binder content using data visualization techniques are detailed, along with standards and criteria for mix performance based on expected traffic loads. By integrating theoretical knowledge with established testing protocols, the chapter equips engineers and practitioners with the tools necessary to design and evaluate asphalt mixtures tailored to varying traffic, climate, and performance requirements.