Between September 1984 and February 1985, cervical cytologic smears were collected from 510 patients using a spatula and an endocervical swab. These smears were compared with those collected from 510 patients between September 1985 and February 1986 using a spatula and an endocervical brush. The use of the endocervical brush increased the number of smears that contained endocervical cells, for both reproductive-age and postmenopausal women. In women without previous radiation therapy, the rate of suboptimal smears (those without endocervical cells) fell from 12.0 to 1.7% when the endocervical brush was used. This modified smear collection technique improved the quality of the cytologic material.