Introduction & Background: Bone marrow is classified into two types of tissues based on differences in their color at gross pathologic examination. The ac-tie hematopoietic component is comprised mostly of erythrocytes and their precursors and is denoted as "red" marrow, whereas "yellow" (inactive) marrow is comprised primarily of fat. Bone marrow is the fourth largest organ in body by weight, following bone, muscle and fat. MRI pattern of bone marrow is de-pendent on several factors including age, sex, differ-end bones, diseases (inflammation, tumors, ischemia, trauma, and metabolic disorders), post-surgical and post-radiation changes. Progressive conversion of hematopoietic marrow to fatty marrow is seen with age. The conversion process continues until the adult pattern is reached by the age of 25 years. Here nor-cal and abnormal appearances of bone marrow in MRI. Role of different MRI sequences (such as T1W Spin echo, T2W fat-saturation (FSE), ORE, fast STIR, etc.) in normal and abnormal bone marrow patterns is also discussed.