Agrobacterium tumefaciens mediated plant transformation is a versatile tool for plant genetic engineering following its discovery nearly half a century ago. Numerous modifications were made in its application to increase efficiency, especially in the recalcitrant major cereals plants. Recent breakthroughs in transformation efficiency continue its role as a mainstream technique in CRISPR/Cas-based genome editing and gene stacking. These modifications led to higher transformation frequency and lower but more stable transgene copies with the capability to revolutionize modern agriculture. In this review, we provide a brief overview of the history of Agrobacterium-mediated plant transformation and focus on the most recent progress to improve the system in both the Agrobacterium and the host recipient. A promising future for transformation in biotechnology and agriculture is predicted.