The effect of the Tb3+ doping content (in the range 0-100 mol%) on the structure (using Raman spectroscopy) and photoluminescence (PL) properties of both rhabdophane-type La1-xTbxPO4 center dot nH(2)O and monazite (-)type La1-xTbxPO4 single-crystal nanorods was investigated. La1-xTbxPO4 center dot nH(2)O was directly obtained by microwave assisted hydrothermal synthesis and La1-xTbxPO4 by calcination of La1-xTbxPO4 center dot nH(2)O at 700 degrees C in air for 2 h. It was found that the characteristic Raman bands shift to higher wavenumbers and become broader with increasing Tb3+ concentration, which is attributed to attendant unit-cell volume reduction. The PL due to the Tb3+ f-f transitions has been studied with continuous and pulsed excitations. The PL intensity increases with doping and is maximum for La0.80Tb0.20PO4 center dot nH(2)O and La0.85Tb0.15PO4, i.e.,for rhabdophane and monazite type structures, respectively. A quenching effect is detected for concentrations below x=0.05, but constant efficiency is obtained at higher doping. The calcination increases the efficiency by a factor around 2 due to the combined effects of water molecules and defect elimination. The PL decay curves reveal a long lifetime attributable to single Tb3+ ions which is almost independent of doping for monazite nanorods (5-4.5 ms), and a shorter one around 0.2 ms most likely due to Tb3+ dimmers.