Lahey and Waldman proposed a temperament theory of conduct disorder (CD). Critical is the hypothesized temperament structure in which three relatively uncorrelated temperament dimensions (i.e., negative emotionality, daring, prosociality) central to CD are theorized to emerge in early childhood. The validity of this hypothesized factor structure in early childhood is unknown. The current study seeks to fill this gap by examining Lahey and Waldman’s hypothesized temperament structure utilizing a Canadian sample (n = 283) of preschoolers. Confirmatory factor analyses (CFAs) were performed to compare the hypothesized relatively uncorrelated temperament structure with two alternative models (i.e., correlated three-factor and single-factor structure). The CFA indicated that the temperament dimensions are present in early childhood and are relatively uncorrelated consistent with previous work at later developmental stages. Of importance, the findings highlighted key gender differences observable at 3 and 4 years of age. The theoretical implications are discussed.