The importance of motivation in learning has been widely recognized. However, due to its multidimensional and complex nature, it appears difficult to synthesize research findings on motivation across studies. Heated debates about the effects of intrinsic and extrinsic motivation on learning and their interaction have been going on since the terms started to be used. Moreover, cultural difference acts as another crucial factor in the field. Using the Trends in International Mathematics and Science Studies 2003 eighth grade mathematics data, this study scrutinized the relationship between pleasure-oriented (intrinsic-related) and productivity-oriented (extrinsic-related) motivation and how they collectively affect students' academic performance in East Asian education systems compared with those from Australia, England, The Netherlands, and the USA. The study found that both types of motivation contributed to East Asian students' mathematics achievement in an additive fashion, whereas extrinsic-related motivation appeared to have a detrimental effect on their Western counterparts' learning. Possible reasons were explored from a cultural perspective. (Contains 2 notes and 4 tables.)