External anatomical measurements have a long tradition in morphometric studies. Recently, three-dimensional laser surface scanners have revolutionized the way such measurements can be obtained. The aim of this study was to quantify measurement error (hereafter ME) and reliability of several linear skull measurements of the red fox obtained with three different techniques: using calipers, and by analyzing two- and three-dimensional digital images. Differences between observers had the highest ME values for most traits, followed by method and replicate. Inter-observer variability contributed the most to total ME. Measurements obtained from calipers and two-dimensional digital images showed high agreement, validating their use in traditional morphometric studies. The laser surface scanner was unreliable when compared with the reference in almost half the traits. To achieve greater accuracy, in future studies full advantage of the device's capabilities should be taken. Objects should be scanned in high definition, from many angles and orientations, and self-calibration should be performed.