Oxidation of guaiazulene (1) with a 2.5 molar amount of m-chloroperbenzoic acid in ethanol at 0 °C for 1 h under aerobic conditions gives a ca. 2:1:1 mixture of meso and two enantiomeric forms of 5,5′-biguaiazulene-3,3′(5H,5′H)-dione (2), which upon recrystallization from dichloromethane-hexane selectively provides the single crystals of its meso form only. The first X-ray crystallographic analysis and the electrochemical behavior on the title meso form are reported.