This study describes epidemiological patterns of Green Tobacco Sickness (GTS) reported to a regional poison center July 24 through September 24, 1991, and investigates the feasibility of using such a center to expand the understanding of GTS. Records from the Kentucky Regional Poison Center (KRPC) for 1991 were searched for exposure reports containing 1 of 3 agents likely to be implicated in GTS. The search identified 104 exposure reports, which were examined, coded and analyzed. Of these, we determined that 78 were likely to represent GTS cases. Of the 78 persons with suspected GTS, 78% were male, 1/2 were aged 22 or younger, 1/4 were 17 or younger, and dermal contact was the usual reported route of exposure. Calls to the KRPC originated in residences (51.0%) and in health care facilities (47.7%). Nearly 1/3 of the calls mentioned more than 1 symptomatic person; exposure reports for these people were categorized as clusters. There were 10 clusters, each containing 2-4 persons. Almost 1/4 of all persons with suspected GTS were admitted to a hospital. This study demonstrates that a regional poison center can be used to expand understanding of GTS.