Objective To investigate lifetime risk of total hip replacement (THR) surgery in the state of Victoria, Australia and to describe temporal trends in THR incidence. Methods We analyzed a retrospective population-based longitudinal cohort of patients who received a primary THR in Victoria from 1998-2009. The factors potentially contributing to changes in lifetime risk were also examined, including temporal changes in THR incidence according to health care setting (public versus private), socioeconomic status, and geographic location (regional versus metropolitan). Results We identified 45,775 patients receiving THR over the time period. For a woman age 20-29 years, the mortality-adjusted lifetime risk rose significantly over time, from 8.49% (95% confidence interval [95% CI] 8.23-8.69%) in 1999-2000 to 10.30% (95% CI 10.07-10.49%) in 2007-2008. For a man age 20-29 years, the mortality-adjusted lifetime risk also increased significantly, from 9.29% (95% CI 8.97-9.58%) in 1999-2000 to 10.27% (95% CI 9.95-10.48%) in 2004-2005, but in contrast to the pattern observed for women, it decreased slightly in 2007-2008 (9.90% [95% CI 9.60-10.16%]). We also identified an increasing number of THRs in private hospitals, in people in middle and low socioeconomic groups, and in rural areas. Conclusion The lifetime risk of THR for women was similar to men, despite a higher burden of hip osteoarthritis, and this warrants further investigation. However, increases in the number of THR procedures performed for patients in regional areas and in lower socioeconomic groups suggest some reductions over time in known disparities.