Dear Editor-in-Chief: World Health Organization (WHO) has begun applying an approach known as Communication for Behavioural Impact (COMBI) in the design and implementation of behavioural-focused social mobilization and communication programmes for communicable diseases prevention and control as well as in Malaysia (1). A cross sectional study was carried out in Selangor, Malaysia to evaluate the effectiveness of the COMBI programme in prevent-ing and controlling dengue. The study conducted had qualitative (in-depth interview and a Focus Group Discussion) and quantitative components which compared the perception (knowledge, attitude and practice) from the community with COMBI and community without COMBI in Selangor. The programme did influenced the KAP of the respondents but only during its implementation weeks. The result from qualitative study was corres-ponded with conclusion made during a discussion in Asia Pacific Dengue Forum in February 2006 in Chiang Mai which listed weaknesses in dengue prevention and control programme in Asia Pacific countries including Malaysia (2). Problems on human resources and fund had significantly affected the sustainability of COMBI Programme in long term (3). A study in two districts in Khamphaeng Phet, Thailand in 2004 showed the same finding (4).The other study on KAP in Sao Paolo, Brazil in 1998 showed that urban residents with high economics and social status had a high level of knowledge on dengue (5).