The present study aims to experimentally investigate the effect of low-frequency oscillations on the performance of a pulsating heat pipe (PHP). A seven-turn 2 mm internal diameter capillary tube with 80 mm long evaporator and condenser section each and 126 mm long adiabatic section has been constructed. The PHP with 50% filling ratio is mounted on a platform that is driven by a linear motor and it experiences in the present work a longitudinal oscillation of 1 mm and 3 mm amplitude while operating in a frequency range of 0–3 Hz. Evaporator and condenser sections are supplied with constant temperature circulating fluid and by measuring its outlet temperature heat input/rejection is calculated. The PHP, which is filled with n-pentane, operates at bottom-mode heating with a filling ratio of 50% for evaporator temperature ranging from 45 °C to 60 °C for a constant condenser temperature of 10 °C. Investigation reveals the decrease of thermal resistance with heat input. It is also observed here that the thermal resistance increases marginally with increasing oscillation frequency but quite significantly with evaporator temperature.