North Jakarta has high incidence of dengue haemorrhagic fever (DHF). To reduce DHF mortality and morbidity, teachers need to be educated on DHF first aid. The purpose of this research is to determine the effectiveness of health education on DHF first aid on private teachers in North Jakarta. Research design was pre-post study and data was taken on September 22nd, 2011. Teachers who attended the session were taken as subjects. Data was taken by questionnaires consisting of 5 questions about DHF first aid, and was tested before and after the education. Data was processed using SPSS version 11.5 and tested with marginal homogeneity. Out of 82 respondents, 34 (41.5%) were female teachers and 48 (58.5%) were male teachers. Pretest results showed level of nowledge as follows: 3 (3.7%) were good, 13 (15.9%) were moderate, and 66 (80.5%) were poor. After the education, it was as follows: 5 (6,1%) were good, 26 (31.7%) were moderate, and 51 (62.2%) were poor. Marginal homogeneity showed significant difference on knowledge before and after the education (p<0.01). To conclude, health education is effective to increase knowledge on DHF first aid.