Workplace discrimination in professional occupations remains an important mechanism through which racial inequality is reproduced. Yet existing research tends to conceptualize discrimination through identifiable incidents or interactions, leaving less understood how workers experience racialized treatment that is diffuse, cumulative, or difficult to translate into institutionally recognizable terms. In order to fill this gap, this research draws on 140 in-depth interviews with college-educated Black professionals to investigate how workers perceive, interpret, and respond to racialized treatment in professional workplaces. Findings reveal a striking uncertainty among participants regarding assessments of discrimination and their broader accounts of workplace life. While participants described racialized comments, differential evaluations, heightened scrutiny, exclusion, disproportionate workloads, and other forms of differential treatment that accumulated across interactions and organizational processes, they often did so without producing a singular incident they considered sufficiently consequential, provable, or reportable as discrimination. Notably, 35% of these accounts came from individuals who had reported experiencing little or no discrimination in a pre-interview survey. I conceptualize this diffuse organizational presence as the specter of discrimination: the pervasive sense that race structures how one is perceived and treated at work even when its effects cannot always be located within a singular, discrete discriminatory event. The specter generates racialized interpretive and vigilant labor as workers scrutinize interactions and organizational decisions, assess their cumulative implications, anticipate future treatment, and, at times, question whether what they experienced was racial discrimination at all. By shifting analytical attention from discrimination as a discrete event to racialization as an organizational presence that is experienced cumulatively across workplace life, this study expands sociological understandings of how racial inequality is perceived, navigated, and reproduced in contemporary professional workplaces.