A study on point defects in lead tungstate (PbWO4) by using positron annihilation lifetime method is presented. The measurement was carried out for the cases of untreated, vacuum-annealed, oxygen- annealed and La-doped PbWO4 crystals. It was found that the components T2, which reflect the positron annihilation in point defects, are different from each other for each case. Some tentative models for the defects are discussed.