We report 16 cases of latex allergy and the diagnostic methods used to determine sensitivity. By history, eight had usually experienced anaphylaxis during operative procedures, and eight experienced contact urticaria. Skin prick tests were positive in all subjects and negative in ten controls. In vitro analysis by ELISA for latex-specific IgE was positive in only three subjects. No adverse reactions occurred during testing. We conclude that prick skin testing is the preferred diagnostic method, and that the in vitro method used in this study has an unacceptable lack of sensitivity.