Abstract Rosette leaves of field-grown common borage contained both γ-linolenic acid (18:3ω6) and stearidonic acid (18:4ω3). Their contents varied during the growing period from 0.5 to 2.6 mg and from 5.7 to 9.0 mg g −1 leaf dry wt, respectively. Approximately the same amount of both acids was found in the stalk leaves. The highest values for total fatty acid content, as well as for both γ-linolenic and stearidonic acid contents, in newly developed rosette leaves were found in late June, whereas in stalk leaves maximum values for all of these parameters were found in September. Under controlled growth conditions the total fatty acid content as well as the content and/or percentage of y-linolenic and stearidonic acids in the rosette leaves were affected to some extent by light intensity.