One of the most important yardsticks for evaluating sampling for the detection of premalignant and malignant cervical lesions is the percentage of smears that contain cells from the transformation zone. Until February 1985, all smears made by around 500 different general practitioners were taken with a modified Ayre spatula. In the period February to October 1985, 24,496 smears of spatula samples and 5,716 smears prepared by combined spatula-Cytobrush sampling were analyzed. With the introduction of the combined spatula-Cytobrush method, the rate of smears containing cells from the transformation zone (adequate smears) rose from 84% to 98%. With the spatula-alone method, there were large differences between the rates of adequate smears from the various doctors; with the combined spatula-Cytobrush method, all participating doctors were without exception highly successful. The positive cytology rate was significantly higher in the combined spatula-Cytobrush smears (0.75%) as compared with the spatula-alone smears (0.38%). There was also a change in the diagnostic pattern in that more premalignant changes of the glandular epithelium of the endocervix were detected. One case of early invasive adenocarcinoma of the endocervix, in which the combined spatula-Cytobrush smears was positive and the repeat spatula-alone smear made by the gynecologist was negative, is discussed in detail. We anticipate that, with the large-scale introduction of the Cytobrush sampling method, fewer repeat smears will be required and, in addition, the observed relative increase of endocervical adenocarcinoma of the endocervix will be halted. In addition, there will be fewer false-negative smears.