A 2 × 6 factorial experiment was conducted to evaluate the effect of
Satureja khuzistanica
essential oils (
SkEO
; 0, 200, 300, 400, 500, and 600 mg/bird/day) administered via oral gavage and dietary acetic acid (
AA
; 0 and 20 g/1 kg) on fatty acids (
FA
) composition in thigh meat of Ross 308 broiler chickens at days 34, 38, and 42 of age. Dietary AA reduced DWG, DFI, and European economic efficiency index, and increased FCR compared with the nonacidified diet. In day 34 of age, saturated FA (
SFA
) percentage reduced and polyunsaturated FA (
PUFA)
, n-3, and n-6 percentages increased in the birds that received 400 mg SkEO. Mean monounsaturated FA (
MUFA
) percentage was greater, whereas PUFA, n-3, n-6, and total FA (
TFA
) percentages were lesser in the birds fed on the acidified diet. In day 38 of age, mean PUFA, TFA, n-3, and n-6 percentages were greater while MUFA and cis FA (
CFA
) concentrations were lesser in the thigh muscle of the birds that received 400 mg SkEO. Mean MUFA, PUFA, n-3, n-6, CFA, and TFA percentages were lower in the birds maintained on the acidified diet. In day 42 of age, mean SFA percentage reduced in the birds given 300 mg SkEO, while TFA percentage lowered in the birds that received 200 and 600 mg SkEO. The acidified diet decreased MUFA, TFA, and CFA percentage and increased SFA and the n-6 to n-3 fatty acids ratio of thigh meat in chicken. The results led to the conclusion that the daily enteral administration of SkEO through oral gavage may feasibly modify the fatty acids profile of thigh meat in favor of increased PUFA. Dietary AA and its interaction with SkEO inconsistently modified concentration of certain classes of fatty acids in broiler thigh meat, particularly in advanced ages. Almost all alterations induced by AA-involving treatments in fatty acids composition of thigh meat were on the contrary to the SkEO influences as they were in favor of an increased SFA proportion.