•Oil yield in the oak acorns of Q. rubra reached 20.1–24.0% vs 3.1–6.3% in Q. robur.•Q. rubra and Q. robur acorn oils are rich in oleic and linoleic acids.•The β and γ-tocopherol are predominated forms in Q. rubra and Q. robur, respectively.•β-Sitosterol constituted over 60% of total phytosterols in acorn oil of both species.•PCA analysis may help to distinguish the acorn oils recovered from different species. The acorns (fruits) of the oak species Quercus rubra L. and Quercus robur L., grown over the world mainly in forests and parks, are usually not collected or utilised, therefore represent a potentially cheap/free source of plant material with potential applications in the processing industry. In the present study, oil recovery and composition from acorns collected from Q. rubra (n=6) and Q. robur (n=7) individuals was evaluated. Oil yields from Q. robur and Q. rubra acorns ranged from 3.1 to 6.3% and 20.1–24.0%, respectively. In the oils of both species C18:1 (28.4–65.7%), C18:2 (24.1–48.0%) and C16:0 (7.5–17.9%) were the main fatty acids with some differences in proportions between species. On average, β-sitosterol constituted 64.3% and 68.1% of total sterol concentration, which amounted to 244.9 and 271.4mg/100g oil in Q. robur and Q. rubra, respectively. Q. rubra acorn oil was rich in β-tocopherol (93%), while Q. robur in γ-tocopherol (96%). A nearly six-fold higher level of total tocopherol content was recorded for Q. robur relative to Q. rubra. Principal component analysis of chemical composition data confirmed their ability to distinguish between Q. robur and Q. rubra samples. The unique and high concentration of lipophilic compounds in both species, and the availability (cheap/free) of acorns, make oak fruits an interesting source of plant material for industrial applications.