Background: In recent years, the examination of the impostor phenomenon (IP) has expanded to Black doctoral student populations; however, studies have only sampled Black students attending predominantly white institutions (PWIs). To date, an exploration of IP in Black students attending historically Black colleges and universities (HBCUs) is relatively uncharted, leaving a considerable gap in the literature. Purpose: The purpose of this study was to examine IP in Black social work Ph.D. students; explore instances of IP in Black social work Ph.D. students attending HBCUs; and, attempted to determine factors that predict IP in social work Ph.D. students. Methods: This quantitative study used a cross-sectional research design to examine contributors to instances of IP in Black social work Ph.D. students. Using a purposeful sample of 209 currently enrolled social work Ph.D. students, participants completed a self-administered survey that included 88-items related to demographic characteristics and institution types as well as four well-utilized scales: (1) Clance Impostor Phenomenon Scale (CIPS), (2) the Minority Student Stress Scale (MSS), (3) Center for Epidemiological Studies Depression Scale (CES-D), and (4) the Survey of Perceived Organizational Support (SPOS) from their respective Ph.D. programs. Data Analysis: Descriptive and inferential statistics were used to describe the sample, the scales, and to test the study hypotheses. Pearson's r was used to determine the correlation between participants' MSS levels and IP scores. A multivariate analysis of variance (MANOVA) was used to determine statistical significance between Black HBCU and Black PWI participants' levels of CIPS, MSS, CES-D, and SPOS. Lastly, the study used a multiple linear regression to determine factors that contribute to impostor scores in social work Ph.D. students. Main Results: The study found negative statistically significant relationships between SPOS (r = -0.31, p < 0.01), MSS (r = -0.22, p < 0.01), CES-D (r = -0.585, p < 0.01), and CIPS. Due to a sample size violation, the study was unable to conduct a two-way MANOVA, therefore a supplemental one-way MANOVA was conducted on institution types (HBCU v. PWI) which revealed significant differences with regard to MSS (F[subscript (1, 200)] = 10.40, p < 0.001) and CIPS (F[subscript (1, 200)] = 19.03, p < 0.001). Lastly, the results of the stepwise multiple regression analysis revealed five factors as significant predictors of impostorism (F[subscript (df = 5, 194)] = 36.91, p < 0.001), with depression identified as the most significant predictor of impostor scores ([beta] = -0.50, p < 0.001), followed by race (white) ([beta] = -0.35, p < 0.001), minority stress scores ([beta] = -0.21, p < 0.001), perceived organizational support ([beta] = -0.13, p < 0.05), and age (35 to 44 years) ([beta] = 0.10, p < 0.05). These factors accounted for a total of 49 percent of the variance in impostor scores. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]