Lumbar apophyseal ring fracture (LARF) is an uncommon injury that occurs during adolescence. We evaluated CT and MR findings of the lumbar apophyseal ring fractures in 35 cases of LARF (CT was performed in 35. MR in 6). CT demonstrated characteristic bony fragments displaced posteriorly into the spinal canal and a corresponding defect in the posteroinferior aspect of the vertebral body rim. Plain film demonstrated only 8 cases (20%) of LARF. MR features included 1) discontinuity and truncation of the posteroinferior vertebral body (100%) 2) displacement of the low signal fragment (37.5%). Recognition of this entity is important in decision of treatment planning.