The title compound, C24H20NSSe+.C24H20B-, exhibits disorder (S/Se scrambling) of the chalcogen sites within the S-N-Se triad. Similar disorder was observed in the bromide salt [Aucott, Bailey, Elsegood, Gilby, Holmes, Kelly, Papageorgiou & Pedron-Haba (2004). New J. Chem. pp. 959-966]. The S-N and Se-N bond lengths are 1.6735 (15) and 1.8045 (14) A, respectively. Whereas the chalcogens in the bromide salt are involved in S...Br and Se...Br interactions of very similar distances, the scrambled S and Se sites in the title compound are involved in distinct non-bonded interactions. The site predominantly occupied by sulfur is involved in C-H...S/Se interactions, while the site predominantly occupied by selenium is involved in Se/S...pi interactions.