We link two important ideas: attention is scarce and lack of information about an individual drives discrimination in selection decisions. Our model of allocation of costly attention implies that applicants from negatively stereotyped groups face "attention discrimination": less attention in highly selective cherry-picking markets, where more attention helps applicants, and more attention in lemon-dropping markets, where it harms them. To test the prediction, we integrate tools to monitor information acquisition into correspondence field experiments. In both countries we study we find that unfavorable signals, minority names, or unemployment, systematically reduce employers' efforts to inspect resumes. Also consistent with the model, in the rental housing market, which is much less selective than labor markets, we find landlords acquire more information about minority relative to majority applicants. We discuss implications of endogenous attention for magnitude and persistence of discrimination in selection decisions, returns to human capital and, potentially, for policy.