The literature on democratic transitions considers the participation of new parties in the first pluralist election in a post-authoritarian context (founding election) as something to be taken for granted. As such, it is never questioned. Specialists in democratic transitions ignore the research on "new parties," which is, nonetheless, essential to the understanding of the particular characteristics of a post-authoritarian situation. Using an original qualitative study on Algeria, this article proposes to bring to light the political, organizational, and legal conditions of new political parties’ participation or nonparticipation in a founding election. In particular, this research allows us to grasp the dilemmas and difficulties faced by leaders of new parties and the types of support on which they rely to engage for the first time in an electoral competition. The analytical framework stemming from this "case study" is applicable to other national case studies.