OBJECTIVES: Unsatisfactory cervical cancer screening cytology samples (Unsats), impose a high financial burden on the healthcare system. Unsats are important because they are more prevalent in women with invasive cervical cancer. The purpose of this study is to estimate the impact of Unsats on the cost of cervical cancer screening programs as well as on patient outcomes in a U.S. population of women. METHODS:  A state-transition Markov model was used to simulate cervical cancer screening and follow-on treatment for a cohort of 1 million U.S. women (21-65 years of age). The screening algorithm used was based on current U.S. cervical cancer screening guidelines which call for primary cytology testing every 3 years for women between the ages of 21 and 65, with an HPV reflex test for those who have an abnormal cytology result. For women over 30, the U.S. guidelines recommend the option of a cytology/HPV co-test every 5 years. Other inputs included U.S. high-risk HPV prevalence; age-specific cervical cancer incidence and associated mortality; age-specific cervical cancer screening and treatment compliance; HPV vaccination rates; and U.S. health care resource cost data. RESULTS:  Unsats are costly to cytology laboratories as all of the costs associated with reprocessing these samples must be absorbed by the labs. Samples for which reprocessing is unsuccessful impose a greater burden on the health care system in terms of the costs associated with patients returning to physicians’ offices for a second sample collection. Some patients who should return for a second collection are lost to follow-up, presenting an opportunity for disease progression. CONCLUSIONS: The Unsat rate associated with a cytology test can significantly increase the effective cost of the test. All costs need to be considered in order to determine the true cost of a cytology test for cervical cancer.