This paper presents an analytical investigation of the enhancement of thermal performance of parabolic trough collector with serrated twisted tape inserts in the absorber tube. The heat transfer equations for fully developed flow under quasi-steady state conditions have been developed in order to analyze thermal efficiency and fluid temperature rise and to study the effect of system and operating parameters. A computer programme, based on mathematical models is developed in C++ language to estimate the temperature rise of fluid for evaluation of thermal performances under specified conditions. It has been found that heat transfer coefficient increases 4.38 and 3.51 times with use of twisted tape insert(with tape twist ratio of 1) at mass flow rate of 0.06 kg/s and 0.16 kg/s, respectively; while corresponding enhancement in thermal efficency is found to be 15.7% and 5.41% respectively.