Organic production methods are perceived by the consumers as a guarantee of safety and good taste. Organic products are considered as of high quality, they also contain less harmful pesticides residues and minerals fertilizers which are used in conventional farming. The comparison of sugars and selected bioactive compounds content in onion from organic and conventional cultivations is shown in this study. Result obtained showed that organic onions contained more total sugar, flavonoids, vitamin C and anthocyanins then conventional ones.