The purpose of this study was to build a comprehensive overview of the potential role of fish in improving nutrition with respect to certain micronutrient deficiencies in developing countries. A comprehensive literature review was completed. The quality of the data was carefully reviewed and data that lacked proper information on methods, units or sample size were excluded. Particular effort was made to highlight not only the information recently generated but also the gap in knowledge where more research is needed. Our focus was on developing countries where the largest proportion of people exposed to risk of undernutrition is found and where 95% of the population depends on small-scale fisheries or small-scale aquaculture for their livelihood.