Firms pursue diversification for sake enhancing financial performance. Some theories state positive relationship between diversification and financial performance. However, there are some theories for negative relationship about the issue. The study has filled the gap that most studies done in developed countries and there are fewer studies in developing country like Malaysia. In this study, researchers try to examine the relationship between product diversification and international diversification with financial performance in manufacturing firms listed in Bursa Malaysia. The study is done in 102 manufacturing firms listed in Bursa Malaysia during 2006 to 2010. Two regression models are run with return on assets (ROA) as a dependent variable. Also, the main independent variables are total product diversification (TPD), related product diversification (RPD), unrelated product diversification (UPD), international diversification (ID). The results show product diversification and unrelated diversification are not significant; however, related diversification and international diversification have negative impact on financial performance.