An Unsatisfactory Pap smear means that the laboratory staff could not see the cells well enough to give a report. The prevalence of detectable Unsatisfactory in Srinagarind hospital was 168 cases of 51,951 collected cases (0.003%). The women with Unsatisfactory cytologic findings in aged more than 60 years old were 73 cases (43.5%), 51-60 years old were 51 cases (30.3%) and younger than 30 years old were 3 cases (1.8%). The most of Unsatisfactory Pap smear found 115 cases (68.5%) in Radiotherapy Unit and 35 cases (20.8%) in Obsterics and Gynaecology (OB-Gyn) Unit. The patients with Unsatisfactory results had found previous check up as abnormal cells 6 cases (85.7%) in Radiotherapy Unit, and 1 case (14.3%) in OB-Gyn Unit. When the patients had been followed up by clinician, the results were abnormal cells 6 cases (66.7%) in Radiotherapy Unit, and 3 cases (33.3%) in OB-gyn Unit. The women lost to follow up 28 cases which found 13 cases (46.4%) in OB-gyn Unit, 7 cases (25%) in Radiotherapy Unit, 4 cases (14.3%) in Examination room after hours Unit, 3 cases (10.7 %) in Examination room during office hours Unit, and 1 cases (3.6%) in Family Planning Unit. The doctors should be an established recall system to notify you when your next Pap smear is due.