Hereditary spastic paraplegia with thin corpus callosum (HSP-TCC) is one of the most common complicated forms of autosomal recessive hereditary spastic paraplegia (HSP). Mutation in SPG11 gene, which is mapped to chromosome 15q21, was recently found to be a major cause of this variant form of HSP. The aim of this study is to investigate SPG11 mutations and clinical manifestations in two Korean families with HSP-TCC. Direct sequencing of the 40 coding exons and boundaries of exon-intron in SPG11 gene, and descriptions of clinical findings in two nonconsanguineous families with HSP-TCC are presented. Three novel and one known compound heterozygous mutations were found in two affected families, which were not found in controls, including one deletion in exon (c.5410_5411delTG), two insertions (c.1834_1835InsT and c.2163_2164InsT), and one missense mutation (c.3291+1G>T). Both of our patients had impairments in frontal lobe functions. We present the first SPG11 mutations in Korean families, three of which are novel. SPG11 mutation should be suspected in Korean patients having HSP with TCC and executive dysfunction.