One hundred thirty-five patients with a reaction of 10 mm or more of induration to 5 TU of intradermal PPD were simultaneously tested with 3 multipuncture techniques to determine the copositivity of the multiple puncture methods with the Mantoux method. Of the 3 multipuncture preparations used (Tine Test, Aplitest, and Mono-Vacc), the Mono-Vacc had 2 (1.5 per cent) false-negative result after 48 hours with only one remaining negative result after 72 hours; whereas the Tine-Test had 21 (15.5 per cent), and the Aplitest had 13 (9.6 per cent) false-negative reactions after 48 hours. Vesicular eruptions were not a commonly noted reaction to the multipuncture preparations. Of the 3 multipuncture preparations commercially available, Mono-Vacc is the preferred reagent because of its significantly lower incidence of false-negative reactions.