Steam-assisted gravity drainage (SAGD) is the most common recovery method for bitumen reservoirs in Western Canada. This method basically consists of a producer and injector, built in parallel, one on top of the other. During the normal operation phase (or SAGD mode), the top well injects steam into the reservoir whereas the bottom one produces bitumen, water, and gas. In the injector well, it is common to consider steam splitters to better manage the steam injection along the reservoir and minimize the required injection pressure at surface. This paper reviews steam splitter application in SAGD injection wells in Western Canada and describes the best practices to achieve appropriate distribution of steam in the horizontal section, gathered after designing dozens of wells in the region and considering the implications of two-phase flow and effective heat transfer in tubulars and the reservoir. Several studies were done for one well using a multiphase flow simulator, including the design of the number of ports, steam flow rate sensitivity, injection only in the tubing and combined injection in tubing and casing, the number of steam splitters, and reservoir heterogeneity. The results are shown in terms of the designed number of ports and steam distribution in each steam splitter, required injection pressure, pressure and temperature profiles, and so on. These results will provide operators with additional insights into the downhole behavior of the horizontal steam injection well, leading to improved performance of SAGD processes and identification of possible challenging operational conditions.