Lead zinc niobate–lead titanate[(1− x )Pb(Zn 1/3 Nb 2/3 )O 3 – x PbTiO 3 ] (PZN–PT) crystals with x =4.5% and x =12% have been investigated using dielectric and Raman measurements over a range of temperatures. Above room temperature, dielectric measurements show that both compositions exhibit structural phase transitions according to the phase diagram proposed by Kuwata et al. [Ferroelectrics 387 (1981) 579]. Below room temperature, an anomaly at around 180 K for the x =12% sample is observed, suggesting another phase transition. Raman measurements are used to study all phase transitions.