This study was to examine the differences in health belief variables and HPV (Human Papillomavirus) knowledge in Pap smears according to the stages of change using Trans-theoretical Model (TTM) among married nurses. METHODS: The research design was a cross sectional survey. Participants were 387 married nurses working in general hospital located metropolitan city. Measurement variables were perceived threatening, perceived severity, benefits of Pap, HPV knowledge and stages of the change in Pap smear. RESULTS: Classified stages were pre-contemplation 3.9%, contemplation 17.8%, relapsing 29.5%, action 31.0%, and maintenance 17.8%. Accuracy rate of HPV knowledge were low ranging from 15% to 45%. Among the variables, perceived threatening (F=3.56, p=.007), perceived severity (F=9.73, p<.001) and HPV knowledge (F=7.52, p<.001) were significantly different by stages of change. CONCLUSION: Application of TTM to Pap smears was efficient to know the nurse's level of health behaviors, Health belief variables and HPV knowledge were main factors to identify the stages of change. The continuation of Pap smears and the education in relation to HPV knowledge should be encouraged for married nurses.