Quercetin is one of the best studied and most abundant flavonoid molecules in plants. Flavonoids are a large group of natural polyphenols that are almost ubiquitously present in the plants. The consumption of fruit and vegetables containing quercetin has been associated with several health benefits. In this study, we examined the impact of dietary quercetin (0, 0.005, 0.05, 0.5 and 1.75% quercetin by weight) on Drosophila melanogaster Meigen, 1830 postembryonic development and histological changes in larvae and females. A possible hormonmimetic (ecdysonergic) activity of quecetin was also studied on polytene chromosomes present in the larval salivary glands. We noticed a decrease in the duration of the larval period of flies raised on 1.75% quercetin diet. Quercetin-fed larvae entered metamorphosis sooner than the control ones. The most dramatic change was observed in larval fat body. Dark round structures were observed in fat body cells from larvae treated with quercetin.