This paper reviews the potential of functional foods in our daily life. A functional food with new ingredients gives an additional function to human health. Above their basic nutritional value functional foods deliver enhanced benefits. The functional food industry is growing rapidly in recent years. Epidemiological studies as well as in vivo, in vitro, and clinical data showed that plant-based functional foods are able to reduce the risk of different chronic disease, such as cancer. These biologically active plant chemicals are known as ‘phytochemicals’. Not only phytochemicals, also there are other animal products considered as functional foods for their potential role in human health. Foods containing probiotics, prebiotics, or plant sterols are also considered as functional foods. The aim of this review was to focus on the role of functional foods on human health. The research work to understand the relationship between different beneficial foods and human health system and to explore the role of the functional foods against various diseases will be an important aspect scientifically, clinically as well as socio-economically. Finally, functional foods will be successful depending on several factors including their effectiveness, safety, and quality.