3-Aminorhodanine reacts with aldehydes to form either 5-[(aryl)alkylidene]-substituted products or Schiff bases or derivatives substituted at both the 3-amino group and the 5-methylene group, depending on the reaction conditions. In this note, synthesis and characterization of 3-amino-5-(pyridin-2-ylmethylidene)-2-thioxo-1,3-thiazolidin-4-one is reported.