ABSTRACT In this study, we aimed to determine the effect of Moringa oleifera essential oil (MOEO) supplementation to rations of Japanese quail ( Coturnix coturnix japonica ) grown under heat stress (HS) on some adipokine (visfatin, adiponectin, and chemerin), intestinal (citrulline), 3,5,3′-triiodothyronine (T3), thyroxine (T4), and thyroid-stimulation hormone (TSH) levels in the serum. For this purpose, 320 day-old male quail chicks were used. The study was conducted over 42 days, including a 7-d adaptation period and a 35-d experimental period. Eight trial groups were established, each including 10 quail: CT (control temperature, 25 ℃), MOEO 200, MOEO 400, MOEO 600, HSC (HS control), SMOEO 200, SMOEO 400, and SMOEO 600. Based on the results, a dose-dependent decrease was observed on days 21 and 42 in serum adiponectin and T3 in the stress and stress-free groups compared with the control group due to MOEO supplementation. The lowest decrease was observed in the MOEO 600 mg/kg dose group. In addition, an increase in stressed groups was observed when examining serum citrulline levels, while chemerin levels did not have a statistically significant effect. While the decrease in serum visfatin, T4, and TSH levels on the 21st day did not have a statistically significant effect, a significant effect was determined on the 42nd day. The addition of MOEO at 600 mg/kg to the ration may be beneficial in preventing intestinal damage and inflammation that may occur due to HS. (MOEO HS visfatin (visfatin chemerin, , chemerin) citrulline, (citrulline) 3,5,3′triiodothyronine 353triiodothyronine triiodothyronine 3,5,3′ 3 5 T3, T (T3) T4 (T4) thyroidstimulation thyroid stimulation (TSH purpose 32 dayold old used 4 7d d 7 35d 35 established 1 temperature 2 ℃, ℃ ℃) 200 400 control, control) results dosedependent dependent stressfree free 60 mgkg mg kg st nd (citrulline 353 3,5,3 (T3 (T4 20 40 6 3,5, (T 3,5 3,