Background: The state of Veracruz, Mexico for 36 years has occupied the first places in new and prevalent cases of patients with HIV and AIDS, occupying during the year 2019 8.7% of the total cases of AIDS nationwide and 12.39% of the total Seropositive cases registered, being important the treatment for these patients to avoid their discrimination since it can be a risk factor for anxiety, depression or suicidal ideation. Objective: To determinate the association between the level of knowledge and attitudes for HIV / AIDS. Methods: A cross-sectional, prospective, analytical and observational study was carried out. High school students from the city of Veracruz-Boca del Río, Mexico were included during the period January - March 2021, students who refused to participate were excluded. The sampling was not probabilistic for temporality and convenience. The knowledge about HIV, stigma, self-efficacy and susceptibility to HIV, was quantified with the HIV / AIDS-65 scale with scores of 0 to 100 likert type. The surveys were conducted through Google Forms® and were by an internet device. For the data analysis the SPSS v22 software, were used, with statistical significance p <0.05. Results: 895 students were included; The correlation between level of correct knowledge and positive attitude, negative attitude, neutral attitude, susceptibility and self-efficacy was less than 0.35 in all cases. Higher quartiles were determined in knowledge scores and the attitude, presenting an OR of 2.3 (95% CI 1.6-3.2) for high self-efficacy, OR 3.1 (95% CI 1.7-5.4) for susceptibility, OR 1.6 (95% CI 1.0 - 2.7) for neutral attitude and OR 2.4 (1.6-3.4) for positive attitude (p <0.05), while the negative attitude resulted with p> 0.05. Conclusions: knowledge has a low correlation with attitude, susceptibility and self-efficacy, and high knowledge is associated with a better attitude, susceptibility and self-efficacy for HIV / AIDS.