Tilapias are an important group of fish, native to Africa, which contribute to food supply in many areas of the world. While there has been a significant increase in production of tilapias globally over the past two decades, there is also some controversy that tilapias cause considerable environmental and biodiversity damage. This publication presents a broad analysis of the overall contribution that tilapias have made and their impact on the Asia-Pacific region. It also discusses the benefits of responsible use of alien species such as tilapias for improving the quality of life of the rural poor.