A backlight assembly includes a light source, a light-guide plate, a reflective sheet, a first prism sheet, a second prism sheet and a lateral reflective sheet. The light source generates light. The light-guide plate guides the light and has a plurality of first prism patterns adjacent to each other. The first prism patterns are formed on a first surface of the light-guide plate. The reflective sheet is disposed adjacent the first surface of the light-guide plate. The first and second prism sheets are disposed on a second surface of the light-guide plate. The lateral reflective sheet is disposed on the second prism sheet. The lateral reflective sheet includes reflective protrusions substantially parallel with a longitudinal direction of the light source. Therefore, brightness and display quality may be enhanced.