We report a STK11 splicing variant comprising a 131-bp insertion that is derived from intron 1, which has previously been reported to possess potent pathogenicity. The same variant was detected in a Peutz-Jeghers syndrome patient harboring a genomic deletion in the vicinity of exon 1 of the STK11 gene, which indicated that this variant was derived from the wild-type allele. We also found the same variant in other normal subjects. This variant corresponds to the predicted transcript variant of STK11 (XM_011528209), which is derived from the genomic sequence of Chr19 (NT_011295.12). Therefore, we concluded that the splicing variant was not pathogenic.