Abstract: The SWI/SNF complex is a multiprotein complex with 10–15 subunits, and it is involved in regulating important cellular processes and functions. It is also frequently mutated, with the most commonly mutated subunit being SMARCA4/BRG1. SMARCA4/BRG1-deficient non-small cell lung cancer (SMARCA4-dNSCLC) is characterized by highly malignant, rapid tumor progression and low survival rates. SMARCA4-dNSCLC often features co-mutations of SMARCA4 and KRAS, TP53, KEAP1, and STK11, but tests for almost all common mutations such as ALK, EGFR, and ROS1 are negative. Thus, traditional treatments may have limited efficacy and new treatment strategies are required. This review summarizes the clinicopathological features of and novel treatment strategies for SMARCA4-dNSCLC.