Confirmatory factor analysis was used to examine factorial invariance across young, middle-aged, and elderly age groups, using Levenson’s multidimensional locus of control (LoC) scale, which measures beliefs in Internal Control (I), Control by Powerful Others (P), and Chance (C). Data were obtained from 563 individuals ranging in age from 25 years to 75 years of age who resided in Southeastern Louisiana. Results indicated that Levenson’s 3-factor conceptualization of control was not a valid representation of the samples’ responses. A model that specified the elimination of 17 unreliable items and the formation of both an internal and an external control factor that was based on the seven remaining I and P items provided an adequate fit to the data for the three age groups, though when additional constraints were specified, factorial invariance was not demonstrated. The 7-item I and P factor model generated a pattern of relationships with other measures which was similar to the pattern found if all items of the I and P scales were used. © 1992 Taylor & Francis Group, LLC.