The main goal of our research was to develop a new measure of persistence and to assess its construct validity and psychometric proprieties. First, we discuss the history of the psychological construct of persistence, defined here as the tendency to remain engaged in specific goal-related activities, despite difficulties, obstacles, fatigue, prolonged frustration or low perceived feasibility. The developed scale, measuring motivational persistence, contains three-factors: long-term purposes pursuing, current purposes pursuing and recurrence of unattained purposes. The results of the two validation studies conducted, employing both exploratory and confirmatory factor analysis, advocate the hypothesized structure. Also, the Pearson and canonical correlations between the three factors of the new self-report scale and other three related measures (and their factors) indicate good levels of convergent and divergent validity of the new scale