Background: Tuberculosis is a major health problem in the world. Pulmonarytuberculosis is a contagious infectious disease caused by a contagious infection bythe bacteria Mycobacterium tuberculosis. This disease if not treated promptly orincomplete treatment can lead to dangerous complications and death. So it isnecessary once to take precautions so as not to infect family members byincreasing knowledge. There are several ways to help prevent tuberculosis fromfriends and family from bacterial infections, namely by opening ventilationrooms, using masks, spitting in certain places that have been disinfected, BCGimmunization, trying sunlight and adequate air intake, drying the mattress,separating all items used by patients.Purpose: This paper aims to describe family nursing care for clients withpulmonary tuberculosis. The focus of the study is lack of knowledge aboutprevention of transmission of pulmonary tuberculosis in the work area of PoncolHealth Center, Semarang.Method: The method used in providing nursing care uses a descriptive methodwith a case study approach and using the nursing approach process. Samplingused includes 2 families.Results: After carrying out family nursing care for 5x meetings on bothrespondents, the results of the two respondents experienced an increase inknowledge about prevention of transmission.