Shigella sonnei is a causal agent of fever, nausea, stomach cramps, vomiting, and diarrheal disease. The present study describes a quantitative polymerase chain reaction (qPCR) assay for the specific detection of S. sonnei using a primer pair based on the methylase gene for the amplification of a 325 bp DNA fragment. The qPCR primer set for the accurate diagnosis of Shigella sonnei was developed from publically available genome sequences. This quantitative PCR-based method will potentially simplify and facilitate the diagnosis of this pathogen and guide disease management.