Twenty immediate denture patients with periodontitis participated in a controlled study to determine the relationship between clinical probing of pocket depth and the connective tissue attachment. Maxillary and mandibular anterior teeth were probed clinically by one investigator to determine attachment levels. The mesial and distal facial line angles were probed from the cementoenamel junction and from a coronal bur groove, to the clinically determined attachment level. One hundred and sixteen teeth were measured. The teeth were extracted, rinsed, and stained with 4% methylene blue in 50% alcohol to demonstrate the remaining connective tissue attachment. A second investigator using the same probe as the first measured the distance from the coronal bur groove and cementoenamel junction to the most coronal extension of the connective tissue attachment. These measurements were repeated by the second investigator using a dividing caliper and a millimeter scale with a Vernier. The data were analyzed by an analysis of variance for grouped teeth, pairwise t statistic for all teeth, and an analysis of variance for all teeth. The results showed: the influence of the interaction between the patients and technique of measurement, bench and clinical, was negligible for the grouped teeth and for all teeth. The difference between the clinical and bench measurements was not significant for all the teeth as well. The null hypothesis that the difference between the clinical measurement and bench measurement is zero was satisified.