Our purpose was to clarify whether subjective symptoms of low-level formaldehyde (FA) exposure in medical students were transient or persistent and to investigate whether the allergy state changed as a result of exposure.

We surveyed the prevalence of medical students’ subjective symptoms and their allergy state before, during, and 6 months after completion of a gross anatomy dissection course by using two self-administrative questionnaires. Students completed the first survey at the end of the anatomy course to assess symptoms before and during the course. The second survey was completed 6 months after course completion.

The prevalence of most subjective symptoms was lower 6 months after the course than during the course. The major symptoms experienced during the course were eye fatigue, runny nose, and dry eyes. The most common symptom 6 months after the course was eye fatigue. Four students continued to experience symptoms even after course completion. Three students developed symptoms only after course completion. Forty-eight students had allergies before the course began and the severity of the allergies did not change after the course. Additionally, the prevalence of most subjective symptoms 6 months after the course was lower than before the course. The patterns of subjective symptoms in the three periods differed between male and female students; the prevalence of most subjective symptoms tended to be higher in females.

Subjective symptoms resulting from FA exposure during a gross anatomy course were transient and did not affect students’ allergy states.