This survey was conducted to obtain answers to some basic questions regarding the timing of root canal obturation. A questionnaire was sent via e-mail to 738 randomly chosen United States endodontists listed in the 1998 to 1999 membership roster of the American Association of Endodontists. One hundred fifty-six replies were received. In pulpectomy cases, root canal obturation at the first visit was carried out by 55.8% of the responding endodontists; in infected root canal cases, the percentage was 34.4%. Of the responding endodontists, 34.2% indicated that their patients had experienced some trouble after root canal obturation at the first visit.