In this study the antioxidant effect of Cannabis sativa L. seeds and sprouts (3 and 5 days of germination) was evaluated. Total polyphenols, flavonoids and flavonols content, when expressed on dry weight basis, were highest in sprouts; ORAC and DPPH (in vitro assays), CAA-RBC (cellular antioxidant activity in red blood cells) and hemolysis test (ex vivo assays) evidenced a good antioxidant activity higher in sprouts than in seeds. Untargeted analysis by high resolution mass spectrometry in negative ion mode allowed the identification of main polyphenols (caffeoyltyramine, cannabisin A, B, C) in seeds and of ω-6 (linoleic acid) in sprouts. Antimutagenic effect of seeds and sprouts extracts evidenced a significant decrease of mutagenesis induced by hydrogen peroxide in Saccharomyces cerevisiae D7 strain. In conclusion our results show that C. sativa seeds and sprouts exert beneficial effects on yeast and human cells and should be further investigated as a potential functional food.