-This paper describes a technique for automating the measurement of brain width and length at the level of the hi-parietal diameter, by processing an axial computed tomography (CT) brain scan image. The development of this algorithm derives from the wish to normalise patient data according to skull size and.shape, for the purpose of comparing new patient data with that fiom past cases. This algorithm uses image processing techniques to find the inner edge of the cavity of the skull. The width and length of the brain are measured as inner dimensions of this hone periphery. The main challenges facing this work are the structural asymmetry of the brain and the angle of rotation commonly encountered whcn working with axial CT images. Both of these must be taken into account prior to measuring the brain width and IengIh. The algorithm was designed and tested to operate on a database containing CT brain scans &om 530 patients. The results indicate that the algorithm bas a 90S6% success rate.