Quantification of reticulo-rumen content (volume and mass) is required in ruminant nutrition research but has traditionally relied on rumen-cannulated animals. The use of computed tomography (CT) is compatible with small ruminants. We compared the reticulo-rumen and omasum volumes measured by CT in vivo with the corresponding digesta masses measured postmortem in Alpine goats (n = 20). Reticulo-rumen and omasum volumes determined by CT were significantly and linearly regressed against the corresponding digesta masses measured postmortem (R2 = 0.72 and 0.87, respectively), thus demonstrating the potential of CT to measure volume and estimate digesta masses of reticulo-rumen and omasum contents in goats.