Following a request from the European Commission, the EFSA NDA Panel was asked to deliver an opinion on pea and rice protein fermented by Shiitake mushroom (Lentinula edodes) mycelia as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is a mixture of fermented pea and rice protein concentrates (65% and 35%, respectively). The NF is proposed to be used as a food ingredient in specific food categories. The target population is the general population. The major constituent of this NF is protein (≥ 75% dry weight), which is well digestible and provides sufficient amounts of essential amino acids. Although a tolerable upper intake level (UL) has not been derived for protein, the protein intake from the NF may nevertheless further contribute to an already high dietary protein intake in Europe. The Panel notes that the cumulative exposure to the nutrients and contaminants analysed does not raise concern. The reported values for the levels of antinutritional factors in the NF are comparable to those in other foodstuffs. The Panel considers that taking into account the composition of the NF and the proposed conditions of use, consumption of the NF is not nutritionally disadvantageous. No toxicological studies with the NF were provided by the applicant; however, the Panel considers that no toxicological studies are required for this NF. The NF has the potential capacity to sensitise individuals or to induce allergic reactions in individuals allergic to pea, rice and Shiitake mushroom. However, this risk is expected not to be higher than that resulting from the normal consumption of pea, rice or the fruiting body of the Shiitake mushroom. The Panel considers that the NF is safe at the proposed conditions of use.