A dithia dication was generated from 4,9-diethyl[1,4]-dihydrodithiino[5,6-f]benzotrithiole 5-oxide on treatment with D2SO4. Hydrolysis of the dication gave 4,9-diethyl[1,4]dihydrodithiino[5,6-f]benzotrithiole 1-oxide and 2-oxide, suggesting that the positive charges, generated on the dithiin ring, transferred to the trithiole ring. A disproportionation of the dithia dication was observed in the solution.