Like other nations experiencing rapid industrialization, urbanization and a nutrition transition, there is concern in Malaysia of a possible escalation in the prevalence of overweight and obesity. In 1996, the National Health and Morbidity Survey reported a 16.6% and 4.4% prevalence of overweight and obesity, respectively. In the following decade, there have been several national and community surveys on overweight and obesity in Malaysia. The objective of this systematic review is to describe the trend from 1996 to 2009 in the prevalence of overweight and obesity in adults in Malaysia nationally and by gender, age and race. Results indicate that there has been a small rise in overweight adults in the years 1996, 2003 and 2006 (20.7%, 26.7% and 29.1%) and a much more dramatic increase in obesity in 1996, 2003, 2004 and 2006 (5.5%, 12.2%, 12.3% and 14.0%). Evidence showed a greater risk for overweight and obesity among women compared with men. Based on the highest-quality studies, overweight and obesity levels were highest among adults 40-59 years old. Overweight levels were highest among Indians, followed by Malays, Chinese and Aboriginals, with less consistency across studies on the order of risk or obesity by ethnicity.