We found an alarming increase in the prevalence of chronic LBP from 1992 to 2006 in North Carolina, which occurred across all demographic subgroups. We also found that acute episodes of LBP (defined as pain that limited usual activities for at least one day, but less than 3 months; or less than 25 episodes of LBP that limited activities) in the past year increased from 7.3% (6.6–8.1) to 10.5% (9.5–11.4). Although the cross-sectional nature of our data prevents any firm conclusions, the smaller increase in prevalence of acute versus chronic LBP is consistent with a greater percentage of acute cases transitioning to chronic cases.