More than 20 types of ALK fusion variant subtypes have been identified, including different fusion partner genes or EML4-ALK fusions with different breakpoints. However, different ALK fusions show different sensitivities to ALK-tyrosine kinase inhibitors (ALK-TKIs) and the emergence of rare fusions brings great challenges to the target therapy in clinic. We report a rare EML4-ALK (E6;A18) fusion in a patient with lung adenocarcinoma that responded well to alectinib. This is the second case of this rare variant reported but the first report of response to an ALK-TKI. This evidence is the first to show that alectinib may be effective for this rare fusion type of non–small cell lung cancer, and these findings have important implications for drug selection in patients with this subtype. Further studies are needed to understand the function of this variant.