This is the first Canadian longitudinal study to use province-wide clinical-administrative data to explore the factors most associated with changing out of home placements. Clinical-administrative child protection data were merged with Canadian Census data for the province of Québec and the final dataset included 29,040 children admitted to out-of-home care for the first time between April 1, 2002 and March 31, 2011. Cox proportional hazard results indicate that older youth, specifically those aged 10 to 13 years at initial placement, have the highest risk to experience the most placement changes over time. The increased risk of placement changes for older youth was statistically explained by a combination of male gender, behavioral problems, school truancy and school neglect, residential or group care at initial placement, request for youth criminal justice services, number of investigations, and neighborhood area socioeconomic disadvantages. Neighborhood area socioeconomic disadvantages were only considered a statistically significant predictor of older youth changing placements at least three times, but not for younger children, or for youth experiencing fewer placement changes.