The cause of familial amyotrophic lateral sclerosis (FALS) has been attributed to mutations in several genes. The authors analyzed these genes, including SOD1, FUS, VAPB, ANG, TDP-43, FIG4, and CHMP2B, in a cohort of 15 index patients of Han Chinese descent with adult-onset FALS. Seven different mutations in eight patients, including three in SOD1 (G85R, T137R, and G138E), two in exon 15 of FUS (H517D and R521H), and two in exon 6 of TARDBP (M337V and N378D) were identified. Among them, T137R SOD1, G138E SOD1, H517D FUS, and N378D TARDBP were novel. No mutation was found in VAPB, ANG, FIG4, or CHMP2B genes. Mutations in SOD1, FUS, and TARDBP account for 20%, 13.3%, and 20% of FALS, respectively. This study defined the distribution and frequency of mutations of FALS in a Taiwanese Han Chinese population, which not only broadens the spectrum of the mutations causing FALS, but also further highlights the importance of FUS and TARDBP in the pathogenesis of amyotrophic lateral sclerosis (ALS).