Low-dimension metal halide perovskites are attractive for bandgap tunable optoelectronic materials. Among them, 1-D CsPbBr 3 quantum wires (QWs) are emerging as promising deep-blue luminescent material. However, the growth dynamics of 1-D perovskite QWs are intricate, making the study and control of 1-D QWs highly challenging. In this study, a strategy for controlling both the length and width of the CsPbBr 3 QWs was realized. The temperature-dependent isotropic growth mechanism was revealed and employed as the main tool for the oriented growth of 1-D CsPbBr 3 QWs for various aspect ratios. Our results pave the way for the controlled synthesis of ultrasmall perovskite nanocrystals.