This study aims to evaluate human papillomavirus (HPV) prevalence and predominating genotypes in liquid-based cervical cytology samples from an Irish urban female population. In addition to use of routine cervical cytology testing, women are screened for HPV using the MY09/11 primers for the HPV L1 gene and primers for beta-globin amplification in a multiplex format. Overall, 996 women between the ages of 16 and 72 years (average age: 35) are included in the study and HPV prevalence was 19.8%. Cytology results showed that 88.9% were normal, 9% borderline or mild dyskaryosis, 1.1% moderate dyskaryosis and 0.9% severe dyskaryosis. Human papillomavirus prevalence in women under 25 was 31%, reducing to 23% in women in the 25-35 age group and to 11% in women over 35. Human papillomavirus prevalence increased with grade of cytology from 11.4% (normal) through 85.4% (borderline), 84% (mild), 100% (moderate) to 100% (severe dyskaryosis). HPV 16 (20%) and 18 (12%) were the most common high-risk types detected in the study. Other common high-risk types were (in descending order) HPV 66, 33, 53, 31 and 58. HPV 66 was associated with the detection of borderline abnormalities by cytology. This is the first population-based study of HPV prevalence in the normal healthy cervical screening population in the Republic of Ireland.