Although cytology laboratories are mandated to rescreen at least 10% of cervicovaginal smears, there is no uniform national rescreening practice. Follow-up data for 16,188 rescreened cervicovaginal smears were studied and decision analysis was performed to determine an optimal rescreening strategy. High-grade dysplasia was detected in 0.40% of women with a history of cervical disease and in 0.04% without a history of cervical disease. Compared with 0% rescreening of smears, with 15% rescreening the cost to gain a year of discounted life expectancy was $386,890 for women without a history of cervical disease, and $2,980 for women with a history of cervical disease. We conclude that rescreening only smears from women with a history of cervical disease could save US laboratories more than $11.2 million annually without seriously compromising care.