Two techniques were used for enriching human breath samples for δ9-tetrahydrocannabinol (I). One method utilized a polyethylene foam wafer which was positioned in front of the expired air stream using a modified face mask. The second technique was a cryogenic trap containing ethanol. Analysis of the enriched breath samples following smoking of a marijuana cigarette was accomplished using a previously described hplc-ms procedure. Results demonstrated that (I) was detectable with either enrichment method following marijuana smoking.