The agrifood industries generate tremendous amounts of waste. Spent coffee grounds (SCGs) have an estimated annual production of 60 million tons worldwide. This exemplifies that a way to enhance and reuse these wastes is necessary, with the aim of achieving a more sustainable, circular economy. Here, we assessed the antioxidant activity of SCG extracted by two different methods, solid--liquid extraction (SLE) and subcritical water extraction (SWE). The extracts were produced, the yield of the extraction was assessed and the total phenolic content (TPC) was evaluated, along with the antioxidant activity, by different assays (DPPH^• and ABTS^•+ scavenging activities and FRAP assay). Two SLE extracts were produced at different conditions, with extract A (1g:50 mL 50:50 water/methanol, 1h extraction time, 40 °C) and B (1g:100 mL 50:50 water/methanol, 1h extraction time, 60 °C). The SWE extracts were produced by mixing 2 g of SCG with 200 mL of ultrapure water at 60 bar and a variation in temperature (100 or 150 °C). Extract A was the one displaying the highest TPC value (134.64 mg gallic acid/ g dry extract) and strongest antioxidant activity. We are currently analysing the SWE extracts for the same parameters. These results will offer valuable information on the impact of different extraction techniques in coffee grounds and their valorisation for food purposes.