We carried out a study of dehydration in natural metamict and crystalline samples of titanite between 20 and 1060 K. Infrared absorption spectra of crystalline titanite show at least five O–H stretching bands in the region between 2000 and 4500 cm−1. Metamict samples show a broad distribution of stretching modes between 2500 and 3700 cm−1. The annealing of metamict titanite was studied by IR absorption spectroscopy under in situ and ex situ heating conditions. Heating a sample at high temperature leads to an irreversible decrease of the absorption signal of the O–H stretching bands, together with a significant sharpening of the band profile. The O–H bands in the metamict material show no preferential polarization. Annealing leads to a dramatic anisotropy of the IR absorption spectra. We believe that the recrystallization behavior of a metamict sample is correlated with its dehydration.