Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver a scientific opinion on “coriander seed oil (CSO)” as a novel food ingredient (NFI) in the context of Regulation (EC) No 258/97. Petroselinic acid (PA) is the major fatty acid in CSO. Conventional edible oil technologies are used to manufacture the NFI. The NFI is intended to be marketed as a food supplement for healthy adults, at a maximum level of 600 mg per day (i.e. 8.6 mg/kg bw per day for a 70 kg person), which would lead to significantly higher intakes of CSO and PA than current background intakes. There are no safety concerns regarding genotoxicity. In rats fed high amounts of CSO, increased liver weight, marked to severe fat infiltration in the liver, and lower tissue arachidonic acid concentrations were observed. In the same study, similar affects were observed when feeding other vegetable oils, although not as severe as that seen for CSO. The dose level of CSO was more than a thousand fold higher than the proposed use level. In a subchronic study using 150, 450 or 1 000 mg/kg bw per day of CSO, a treatment-related effect was observed on blood glucose concentrations of male rats. Although this effect was not accompanied by any toxicological findings, its biological relevance is unclear and therefore the Panel considers the dose level of 450 mg/kg bw per day to be the NOAEL in rats. This is more than 50 fold higher than the proposed use level. No treatment-related adverse effect was observed in one human study using the NFI at the proposed use level for six months. The Panel concludes that the novel food ingredient, CSO, is safe under the proposed uses and use levels.