In recent years, thiolate-protected gold and silver nanoclusters (or Au and Ag NCs for short) with core sizes <2 nm have emerged as a new direction in nanoparticle research due to their discrete electronic transitions and intriguing molecular-like properties, such as quantized charging and strong luminescence. Synthesis of monodisperse (with atomic precision) or highly luminescent Au and Ag NCs is pivotal to realizing their potential in both basic and applied research. This chapter summarizes recent advances in the development of novel synthetic strategies for high-quality thiolate-protected Au and Ag NCs with an emphasis on the underlying principles for achieving atomic precision or strong luminescence.