Abstract A new 1,2,3-thiadiazole compound, C18H18Cl2N4O2S, has been synthesized and the crystalstructure was determined by single crystal X-ray diffraction study. The fungicidalactivity of the title compound was determined and the results showed that it displays moderate fungicidalactivity. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus