Antiradical and total antioxidant activities of extracts from raw, prepared for inoculation, fermented (tempeh) and cooked seeds of grass pea (Lathyrus sativus Krab and Derek cultivars) were measured. Tempeh fermentation with Rhizopus oligosporus resulted in higher scavenging activity towards DPPH and ABTS(+) radicals which correlated well with the content of total phenols. In Derek cultivar, fermentation caused a significant inhibition of linoleic acid oxidation by methanol extracts. In buffer extracts the highest TAA values were observed in raw seeds. Cooking of seeds lowered RSA values as compared to fermentation, especially for the DPPH assay. Methanol and buffer extracts from cooked seeds showed prooxidant activity towards linoleic acid.