The reasons behind consumer participation in the Sharing Economy (SE) are analysed in this research. Special attention is given to more profound and hidden motives for consumer behavior, namely the orientation – individualistic/idiocentric or collectivist/allocentric (Triandis & Gelfand, 1998) – of individuals of a given culture. Meaning: does an individualistic/idiocentric orientation (in a “selfish” and “opportunistic” perspective without any kind of collectivist concerns that they are participating in something that is for the good of society and community as a whole) and/or a collectivist/allocentric orientation (in an “altruist” perspective, towards a collectivist/communal orientation) play a central role in determining consumers’ willingness to participate in sharing-based programs (SBP) of the SE? Furthermore, what intensifies such correlation? Meaning: what moderates the intensity of the relation between those three variables (independent variables: individualism and collectivism; dependent variable: willingness to participate)? In searching for an answer, this research conducted one study divided into two phases: 1) Correlation analysis – with the aim to find out whether these three variables are associated or related in some way, in other words, whether Individualism and/or Collectivism have a positive, a negative or no effect whatsoever on the willingness to participate in SBP of the SE; 2) Moderation analysis – with the aim to find out what moderates (what intensifies) consumers’ participation in SBP of the SE. Having Portuguese consumers as our targeted population, our tentative findings are expected to reveal that (i) both individualistic and collectivistic oriented consumers participate in the SE and (ii) what determines each of these two groups to intensify their participation in SBP of the SE is the level of “pure sharing” or “pure exchange” characteristics that a given SBP has. This work presents an innovative research, as, to the best of our knowledge, it is the first in investigating (i) how individualism and collectivism do play a determinant role on how consumers behave towards SBP of the SE, and (ii) what moderates their participation in SBP of the SE.