To assess whether high school chemistry teachers had higher urinary mercury concentrations than other high school teachers, 24 high school teachers from nine schools in northeastern Ohio were studied. First morning voided urine samples and air samples from the teachers' classrooms were analyzed for total mercury content by cold vapor atomic absorption. The median adjusted urinary mercury concentration in the 12 chemistry teachers was 4.6 microg/g creatinine (range 2.2-8.2 microg/g creatinine) and it was 6.3 microg/g creatinine in the 12 non-chemistry teachers. All classroom air samples contained mercury levels below detection limits. No evidence was provided that high school chemistry teachers are at increased risk of chronic mercury exposure from their teaching activities compared to other high school teachers.