During the past years, the communication activities on the leprosy prevention have been made regularly but there is not any assessment on the knowledge of public or pupils on this disease. This study aims to assess the knowledge of leprosy, attitude and behavior of pupils towards the leprosy patient/the leprosy patient's family, and the effectiveness of the communication activities in the program on leprosy prevention. This is the cross-sectional study with interviewing of 3,000 pupils of secondary schools in Hanoi in 2010 Results: 12.7 percent of interviewed pupils have full and right knowledge, 60.3 percent of them not have full knowledge and 22.3 percent have poor knowledge. 34.2 percent of them are scare and/or afraid of direct communicating with the leprosy patients, but 80.7 percent of them are ready to support the leprosy in any forms. Of which 30.4 percent are ready to support with the material, and the remaining provide the support in form of encourage, comfort and help other people to understand about the disease. The basic communication and education activity on leprosy to the pupils in secondary schools is not effective as required. Recommendations: The communication and health education program need to be prioritized and kept moving forward. The forms of communication are mass media campaign and integrating the lecture of leprosy into the school's curriculum of the secondary schools.