The purpose of the present study was to conceptualize maladaptive forms of sport perfectionism by determining the factors (and items within each factor) that best describe this construct among skilled male and female athletes. The sample consisted of 217 undergraduate student athletes ranging in age from 19 to 33 years. A theory-driven four-factor, 18-item Likert-type scale, called the Sport Perfectionism Inventory (SPI), was generated for this study. The factors, each reflecting maladaptive perfectionism to an excessive degree, included the following: concern over mistakes (CM), self-criticism (SC), personal standards (PS), and negative feedback (NF). Results showed that the items were generalizable for both genders, and all correlations between factors in the scale were significant. It was concluded that these dimensions depicted maladaptive sport perfectionism as a function of gender.