Objective: To analyze the representations constructed by people living with HIV on the infection and their influence on the late search for diagnosis. Method: A qualitative study, conducted through an open interview with people who had a late diagnosis of HIV infection. The theoretical framework adopted was the Theory of Social Representations based on a critical approach. For data analysis, was used the Structural Analysis of Narration method and the MAXQDA 12® software. Results: Eighteen people participated in the study. The following original representations were unveiled: AIDS as a transmissible and dangerous disease; disease of the other; severe, incurable and deadly disease; and denial of risk due to trust in a steady partner. These representations contributed to the late search for diagnosis, either because of the attitude of distance from susceptible people, or because they did not perceive or deny the risks to which they were exposed in their life trajectories. Conclusion: Understanding the reasons that lead people to a late diagnosis of HIV is imperative in the current epidemic scenario for the planning and implementation of new strategies and policies for the timely diagnosis of the infection.