The consumption of organic food has been increasing all over the world. Due to this fact, there are growing numbers of scientific studies examining the nutritional value of organic food. The aim of this review is to provide an overall picture of the beneficial and harmful nutritional content of organically and conventionally produced crops based on existing international comparative surveys. Furthermore, the authors attempt to define the relationship between organic and conventional food production systems and the nutritional value of food products as well as the consumption of organic and conventional diets which have important human health implications. Organic crops contain a significantly higher amount of certain antioxidants (vitamin C, polyphenols and flavonoids) and minerals, as well as have higher dry matter content than conventional ones. Moreover, there is a lower level of pesticide residues, nitrate and some heavy metal contaminations in organic crops compared to conventional ones. There is a relationship between the different fertilisation and plant protection methods of these two plant production systems and the nutritional composition of crops. Consequently, it can be concluded that organically produced plant derived food products have a higher nutritional value, including antioxidants than conventional ones. Furthermore, due to the fact that there is a lower level of contamination in organic crops, the risk of diseases caused by contaminated food is significantly reduced.