In the present study, the effect of receiver position error on the optical and thermal performance of a parabolic trough collector (PTC) has been studied. Optical analysis of the PTC has been carried out by using Monte Carlo ray tracing (MCRT) method. The solar heat flux profile obtained from the optical analysis is coupled with the finite volume method (FVM) to study the thermal performance of the PTC. Simulations have been done for experimental SEGS LS2 solar collector used in Sandia National Laboratories. Syltherm 800 has been considered as heat transfer fluid (HTF). Receiver position errors in two directions i.e. along optical axis and lateral direction, have been taken. Results show that the receiver position error substantially influences the solar heat flux distribution and hence the temperature distribution on the absorber tube. The maximum circumferential temperature difference over the absorber tube increases up to by 199.7 K with receiver dislocation along the optical axis. The effects of the receiver position error on the optical efficiency and collector efficiency have also been studied. A maximum drop of 32% in the optical efficiency is observed when the receiver is displaced from the focus by 1.63% of focal length of the collector in both directions. The collector efficiency decreases by up to 14% when the receiver is offset by 1.63% of focal length of the collector along optical axis (away from the trough).