Abstract. Despite the multiple phenotypic presentations of impulsivity, the underlying factor structure of the construct has yet to be settled. The aim of this study, with two multimethod, multisource datasets, was to further explore the multifactorial nature of impulsivity and propose a measure-selection approach. Unlike previous studies that relied on a single type of statistical analysis, the current study explored the relations between personality and behavioral measures of impulsivity utilizing exploratory factor analysis (EFA) and principal component analysis (PCA). Participants comprised two samples of young adults (n(study 1) = 175 and n(study 2) = 118) from separate communities in southwestern Ontario, Canada. Various facets of impulsivity were assessed including adult ADHD symptoms, planning and organizational skills, executive dysfunction, impulsive personality traits (i.e., sensation-seeking), risk-taking behavior, disinhibition, cognitive flexibility, and delay discounting. Both statistical analyses yielded two-factor models. The Dysexecutive Control factor reflected a tendency to act without thinking or planning, and difficulty focusing for a sustained period of time. The Reward-Seeking factor reflected a general need for excitement, and a preference for novel situations despite adverse consequences. For the purposes of standardized assessment of cognitive, emotional, and behavioral manifestations of impulsivity, trans-theoretical measure selection for research and clinical purposes is discussed.