Background: Pulmonary tuberculosis is epidemic disease it is a one cause of death worldwide it caused by bacteria (Mycobacterium tuberculosis) that mostly infect the lungs. Tuberculosis is curable and preventable disease. Transmission of TB is through the air, when person with pulmonary tuberculosis spit, cough, or sneeze, the microorganisms spread in the air. Few germs can cause infection with tuberculosis. About 1/3 of the population has latent tuberculosis, latent means there is an infection with tuberculosis bacteria but a person still not ill and cannot transmit the disease. Main objective (aim): The study aimed to evaluate the knowledge of secondary school students about pulmonary tuberculosis. Subject and Methods: This is a cross-sectional study, done on the secondary school students in Tikrit city at the period of time from first of January to rst of April 2016. Cluster sampling chosen then students selected randomly from each cluster. Sample size was 98 students was collected by questionnaire, then summarized and presented in simple tables and figures. Result: The study found (57.14%) of students were having some information about pulmonary tuberculosis. By education, we were trying to improve their information about the disease and learn the others "who didn't have any information about the disease" By comparison the results were yield by questionnaire, the students respond very well to the awareness seminar. Conclusions: Students don't have enough information about the disease relation to its epidemiological spread in Iraq. Health education of the students improves their information. Recommendations: perform a program of health education in schools, universities, for patients and for the general population about tuberculosis.