Religious or philosophical conversion can be considered as a form of identity transformation. Within a given cultural environment, the convert tells its story based on standard narratives circulating in this environment. These narratives generally emphasize the unexpected and sudden character of conversion: it does not result so much from the effort of the convert, but rather from a divine initiative or, at least, from the attraction power of the meaning-system to which the convert has accessed. Contemporary psychological models of conversion moderate this description by showing that it consists of a posteriori reading that blurs the long temporality of the process. It is also important to take into account the inevitable negotiation that the convert had to carry out with the social environment until he or she reaches the recognition of the identity transformation that he or she claims. For to speak of conversion presupposes an exclusive conception of religious affiliation, a conception that is not universal but more or less strongly valued only by certain religious traditions. Faced with this exclusive conception, are the motivations of the individual: what drives him or her to convert, what are his/her interests to do it ? Depending on the case, the conversion will result rather from a preference of the individual to build his/her identity in an environment that does not impose it, or rather from constraints imposed on him/her who has no other choice if he/she wants to be admitted to the group he/she wants to join. To shed light on the role of narrative in these interactions, the contribution of sociological and narrative approaches will also be mentioned.