The phenomenon of cavitation generally appears close to yielding in the high-density polyethylene. It can affect the yield stress and the properties at large strains. The influence of the microstructural and molecular parameters on cavitation is not well established; it is not even clear whether the cavitation is a cause or a consequence of plasticity. In this work, we focus on the initiation of cavitation and on the nucleation rate. Various polyethylenes with a wide range of microstructural and molecular parameters have been obtained. The cavitation is followed up by SAXS in-situ tensile tests. It is found that, depending on the polyethylene, cavitation can be avoided or, on the contrary, appears before or after yielding. The stresses necessary to initiate cavitation and crystallite shearing have been relied respectively on stress transmitters (tie molecules, interphase, etc.) and crystallite thickness. Then the comparison between the materials has allowed predicting the various polyethylene behaviors. All of the latter have been explained by a simple model based on very few microstructural parameters. Surprisingly, our results have shown that all the scenarios of plasticity and cavitation are possible. One is the cause or the consequence of the other in accordance with the molecular topology and the microstructure.