The prevalence of cervical cancer is high among some groups of immigrants. Although there is evidence of low participation in cervical cancer screening programs among immigrants, studies have been subject to selection bias and accounted for few immigrant groups. The aim of this study was to compare the proportion of several groups of immigrants versus nonimmigrants attending the cervical cancer-screening program in Norway. In addition, we aimed to study predictors for attendance to the screening program. Register-based study using merged data from four national registries. All Norwegian-born women (1?168?832) and immigrant women (152?800) of screening age for cervical cancer (25-69 years) registered in Norway in 2008 were included. We grouped the immigrants by world's geographic region and carried out descriptive analyses and constructed several logistic regression models. The main outcome variable was whether the woman was registered with a Pap smear in 2008 or not. Immigrants had lower rates of participation compared with Norwegian-born women; Western Europe [adjusted odds ratio (OR), 95% confidence interval (CI): 0.84, 0.81-0.88], Eastern Europe (OR 0.64, 95% CI: 0.60-0.67), Asia (OR 0.74, 95% CI: 0.71-0.77), Africa (OR 0.61, 95% CI: 0.56-0.67) and South America (OR 0.87, 95% CI: 0.79-0.96). Younger age, higher income, residence in rural areas, and having a female general practitioner (GP) were associated with Pap smear. Longer residential time in Norway and having a nonimmigrant GP were associated with screening for some immigrant groups. Appropriate interventions targeting both immigrants and GPs need to be developed and evaluated.