The purpose of this study was to investigate the patterns in allegations of workplace discrimination by individuals with substance use disorders (SUDs). The goal of the research was to describe the discrimination, both actual and perceived, that has occurred against individuals with SUDs through analysis of the United States Equal Employment Opportunity Commission (EEOC) Integrated Mission System (IMS) database in comparison to a group of individuals with other physical disabilities (GENDIS) as defined by the Americans with Disabilities Act (ADA). An ex post facto, causal comparative quantitative design was used with the EEOC IMS database to examine the ADA Title I complaints received by the EEOC from people with SUDs from 1992 through 2011 (n = 8,432) in comparison to the GENDIS group over the same time period (n = 82,618). Results revealed statistically significant differences in the pattern of issues alleged by the two groups. The SUD group was, on average, significantly younger, had a significantly higher proportion of males, had proportionally more individuals who identified as Caucasian and as Other, and proportionally fewer individuals who identified as Hispanic/Mexican and Asian than did the GENDIS comparison group. People with SUDs were significantly less likely than the GENDIS group to have their allegations result in a merit-based case resolution. Implications for counseling practice as well as counselor education and supervision are discussed. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]