The present study, using 14C-DMSO, established the systemic and local load and distribution of topically applied DMSO in adjuvant arthritic rats. Under equivalent conditions, the antiinflammatory effects (systemic and local) of topical DMSO treatments were compared with a topical treatment of a control vehicle or of indomethacin, a known effective antiinflammatory agent. No significant systemic or local antiinflammatory effect of topical DMSO was seen in the adjuvant arthritic rats. Indomethacin, applied topically, had a significant systemic antiinflammatory effect; however, no significant local antiinflammatory effect of indomethacin was observed.