Abstract: In this presentation, we discuss recent progress on the understanding of the self-oscillations in the Pulsating Heat Pipe (PHP). A PHP is a small tube, closed at one end and open at the other. A single vapor bubble sits at the closed end, followed by a single liquid plug and then air. Increasing the temperature of the heater above a threshold leads to oscillations of the liquid plug, growing in amplitude and eventually reaching a steady-state. One may ask basic questions on the dynamics such as: 1) why the system exhibits an oscillatory behavior, 2) what explains the growth of amplitude and 3) what explains the steady-state regime and how to predict the final amplitude. We show how linear stability analysis, normal forms, energy analysis techniques and averaging enable us to answer those questions.