Tuberculosis (TB) is the leading cause of death among people living with HIV (PLWH). Limited TB knowledge has been associated with delayed TB diagnosis and low adherence to TB treatment. A cross-sectional study was conducted among PLWH at the largest HIV-referral center in Lima, Peru, to describe TB knowledge among PLWH and potential associated sociodemographic factors. Participants answered a self-administered survey on TB knowledge, which consisted of five questions about TB cure, transmission, treatment, symptoms, and prevention. Of 179 PLWH enrolled, most participants did not know that isoniazid (85%) and antiretrovirals (78%) are preventive measures for TB, and 56 (31.3%) knew that TB can be asymptomatic in PLWH. We did not find statistical differences in TB knowledge based on gender, education, marital status, and time on HIV care. We identified important gaps in TB knowledge among PLWH. Addressing these gaps could empower PLWH to reduce their TB risk.