A method and system for automatic MR brain scan planning is disclosed. The method utilizes a set of 2D orthogonal localizer images to determine scanning planes for 3D diagnostic MR scans. A location of the mid-sagittal plane (MSP) is detected in each of a transversal localizer image and a coronal localizer image. A sagittal scanning plane is determined based on the location of the MSP in the transversal and coronal localizer images. A diagnostic sagittal MR scan is then acquired based on the sagittal scanning plane. The corpus callosum CC is segmented in a sagittal MR image slice resulting from the diagnostic sagittal MR scan. A transversal scanning plane can be determined based on a location of the CC in the sagittal MR image slice and the location of the MSP in the coronal localizer image, and a coronal scanning plane can be determined based on the location of the CC in the sagittal MR image slice and the location of the MSP in the transversal localizer image.