BACKGROUND Red pepper seeds account for 450–500 g kg−1 of the total pepper weight and often are ignored. Process optimization and characterization of fragrant oil from roasted red pepper seed extracted by subcritical butane extraction were carried out in this study. RESULTS The optimum conditions of the extraction were: extraction temperature 74.61 °C, time 38.65 min and liquid–solid ratio 30.24:1. The oil had refractive index (25 °C) of 1.471, relative density of 0.900, acid value of 1.421 mg/g oil, iodine value of 127.035 g/100 g, saponification value of 184.060 mg KOH/g, unsaponifiable matter of 12.400 g kg−1, peroxide value of 2.465 meq. O2/kg, and viscosity of 52.094 cP. The main fatty acids in the oil were linoleic acid (72.95%) followed by palmitic acid (11.43%) and oleic acid (10.00%). The oil showed its desirable thermal and oxidative stability. A total of 19 volatile compounds, mostly aldehydes and alkenes were identified from the oil. CONCLUSION The results indicated that the method is appropriate for the preparation of fragrant red pepper seed oil, and the oil is suitable for used as edible oil.