SummaryIn this study, the effect of roasting on the oil quantities, bioactive properties, colour, fatty acids and polyphenols of seeds roasted in pan at roasting times was investigated. Total phenolic and flavonoid quantities of roasted seeds are assayed among 186.59 (control) and 429.29 mgGAE/100 g (20 min) to 810.00 (10 min) and 903.33 mg/100 g (5 min), respectively. The heat treatment increased the oil and total phenol quantities of the chia seeds compared to the control, depending on the increase in roasting time. In addition, the antioxidant effect of the seeds in the 5‐min roasting process was the same as in the control, but it showed differences with other roasting times. As the roasting time increased, a significant increase was observed in the L* values of the seeds and this reduced the brightness of the seeds. The 3,4‐dihydroxybenzoic acid and catechin quantities of the chia seeds roasted for 15 and 20 min were higher than the 3,4‐dihydroxybenzoic acid and catechin amounts of control and chia seeds roasted for 5 and 10 min. Linolenic acid was found to be the highest in chia oils, and its amount changed between 63.66 (20 min) and 66.88% (control).