Morphometry is defined as studying variations in and changes of shapes. Evaluation of shape changes in the brain is a key step in the development of new mouse models, the monitoring of different pathologies, and measuring environmental influences. Traditional morphometry was performed by manual shape delineation, so-called volumetry. Currently, automated methods have been developed that can be roughly divided into three groups: voxel-based morphometry, deformation-based morphometry, and shape-based morphometry. In this chapter, we describe the different approaches for quantitative morphometry and how they can be applied to the quantitative analysis of the rodent brain.