This chapter examines key variables influencing 3D printed concrete performance, focusing on material, process, environmental, and geometric factors essential for achieving optimal strength and durability. It begins with an overview of 3D printed concrete, performance metrics, and the scope of the study. The chapter then delves into material composition, discussing how cement type, aggregate characteristics, additives, and water-cement ratios affect mix consistency, workability, and structural integrity. Process parameters, such as layer height, print speed, and extrusion rate, are analysed for their impact on layer adhesion and structural stability. Environmental factors—including temperature, humidity, and curing—are examined, highlighting their influence on setting time and strength. Geometric and structural considerations, like wall thickness and layer bonding, reveal the effects of design complexity on stability. The chapter concludes by synthesizing these findings, offering insights into optimizing 3D printed concrete performance through coordinated control of materials, process, and environmental conditions.