In the study of disease mapping, relative risk estimation is the focus of analysis. Many methods have been introduced to estimate relative risk. In this paper, one of the common spatial models known as Besag, York and Mollié (BYM) model is discussed, and its application to dengue data for epidemiology weeks 1 to 52 of the year 2013 for 16 states in Malaysia is studied. Findings show that Selangor has the highest relative risk of dengue in comparison with other states. Data on the estimated relative risks are presented in the form of risk maps which can be used as a tool for the prevention and control of dengue.