Background: Tuberculosis (TB) case detection in Peru relies on passive case finding. This strategy relies on the assumption that the community is aware that a persistent cough or contact with a TB patient is an indication to seek formal health care. This study evaluated health literacy and TB knowledge among outpatients at Hospital Cayetano Heredia in Lima, Peru. Methods: A cross-sectional survey was performed between June and August 2017. Data on sociodemographic factors, TB knowledge, and health literacy were collected, and bivariate and multivariate logistic regressions were performed to study the associations between variables. Results: The analysis included 272 participants; 57.7% knew someone who had TB and 9% had TB in the past. A 2-week cough was reported as a TB symptom by 66 (24%) participants. High TB knowledge was found among 149 (54.8%) participants and high health literacy was found among 193 (71.0%) participants. Health literacy and TB knowledge were not significantly associated (OR=0.9; 95% CI 0.5-1.5). After controlling for sex, age, district, education, health insurance, frequency of hospital visits, and previous TB diagnosis, high TB knowledge was associated with knowing someone with TB (aOR=2.7; 95% CI 1.6-4.7) and inversely associated with being a public transport driver (aOR=0.2; 95% CI 0.05-0.9). Not living in poverty was the single factor associated with high health literacy (aOR=3.8; 95% CI 1.6-8.9). Conclusion: Although TB knowledge was fair, 30% did not know that cough is a symptom of TB and >70% did not know being in contact with a TB patient is a risk factor for TB. Tailoring educational strategies to at-risk groups may enhance passive case detection especially among transport workers and TB contacts in Lima, Peru.