Abstract: The effect of fast neutron bombardment (2 Mev 252Cf source) with fluence of 1.07 × 1010 n/cm2 on the linear thermal expansion of Li-β-alumina ceramics was studied. Two ceramic groups in which the contents of oxides of Li, Na, K as well as B increased at the expense of alumina were prepared. Induced defects in terms of X-ray diffraction analysis were discussed to assess the use and applicability of these ceramics in neutron dosimetry. The thermal expansion data indicated that both groups exhibited reduction in the mean thermal expansion coefficient values upon irradiation. This is parallel with the shift in the lattice planes of the group with higher alumina and amorphism in the other one. Annealing of the neutron induced defects at 1000°C denoted that partial recovery in higher aluminous group is detected. Approximately complete recovery in the other group revealed a higher state of metamictization.