A　reduction　in　gray　matter　volume　is　common　in　patients　with　chronic　back　pain,　and　different　types　of　pain　are　associated　with　gray　matter　abnormalities　in　distinct　brain　regions.　To　examine　differences　in　brain　morphology　in　patients　with　low　back　pain　or　neck　and　upper　back　pain,　we　investigated　changes　in　gray　matter　volume　in　chronic　back　pain　patients　having　different　sites　of　pain　using　voxel-based　morphometry.　A　reduction　in　cortical　gray　matter　volume　was　found　primarily　in　the　left　postcentral　gyrus　and　in　the　left　precuneus　and　bilateral　cuneal　cortex　of　patients　with　low　back　pain.　In　these　patients,　there　was　an　increase　in　subcortical　gray　matter　volume　in　the　bilateral　putamen　and　accumbens,　right　pallidum,　right　caudate　nucleus,　and　left　amygdala.　In　upper　back　pain　patients,　reduced　cortical　gray　matter　volume　was　found　in　the　left　precentral　and　left　postcentral　cortices.　Our　findings　suggest　that　regional　gray　matter　volume　abnormalities　in　low　back　pain　patients　are　more　extensive　than　in　upper　back　pain　patients.　Subcortical　gray　matter　volume　increases　are　found　only　in　patients　with　low　back　pain.