There are two directions in researching perfectionism: in relation to its consequences and in relation to its characteristics and dimensions. However, this research explored the concept of the unidimensional perfectionism which is supposed to be two-dimensional, containing a manifest and an experiential component. Perfectionism is correlated with many fields of human behavior. For that reason, in this study the correlation with the situational efficiency parameters in basketball was explored. The basic goal of this study was to determine the relation between the manifest and the experiential perfectionism with standard and derived situational efficiency parameters in basketball. Participants in the survey were the basketball players (N = 74) pertaining to nine teams that have performed in the first stage of the Croatian Championship in basketball, members of theA-1 League Championship in season 2006/2007. The Burns Short perfectionism scale with 10 items was applied (adapted version of the Croatian population). Data about basketball performance were collected from the official statistics about the games played in championship. After determining metric characteristics of the questionnaire, and quasi-confirmatory factor analysis, total scores for two dimensions of perfectionism were calculated. Correlations between two dimensions of perfectionism with the standard and derived situational efficiency parameters in basketball, were found. This research has shown the possibility for dividing unidimensional perfectionism in two dimensions. Dimensions of a manifest and a experiential perfectionism component didn't show a significant correlation with the derived, as well as with the standard parameters of efficiency of basketball. Analysis of single correlations points to the fact that "desirable" situation parameters positively are more positive correlated with a manifest perfectionism.No statistically significant correlation between manifest and experiential perfection with standard and derived parameters of situational success in basketball was established. However, a large number of significant individual correlations point to the importance of future research.