Lanthanide ion doping of lead titanate was investigated using structural and differential scanning calorimetry measurements. Dense ceramics samples were prepared with starting compositions, Pb(1-3x/2)Ln (x) TiO(3), assuming A-site substitution of Ln = La, Nd, Sm, Eu, Gd and Dy, at 2 and 8 at.%. Doping with La(3+) reduced the tetragonality and cell volume. A systematic recovery in these values was observed for the smaller Ln(3+) ions, suggesting the onset of partial substitution of the Ln ions at the B-site. The ferroelectric-paraelectric transition temperatures also recovered, consistent with an increased probability of B-site occupation with decreasing ion size. Evidence for site occupancy obtained from the presence cation vacancies is also discussed.