This study was conducted to investigate the impact of thyme (Thymus vulgaris l.) and lavender (Lavandula augustifolia m.) oils supplementation and their combination in broiler's diet on productive performance and some blood parameters. A total number of 120 broiler chicks (Arbor Acres) of one-week old were used in this study. Birds were randomly divided into 4 groups. The birds in each group were distributed to 3 replicates, 10 birds each. The first group (T1) was served as a control group and received only a basal diet. The 2^nd group (T2) was fed basal diet supplemented with thyme oil at level of 0.4 ml/ kg diet. The 3^th group (T3) was fed basal diet supplemented with lavender oil at level of 0.5 ml/ kg diet and 4^th group (T4) was supplemented with mixture of thyme and lavender oils at levels of 0.4 and o.5 ml/kg diet, respectively. Results showed that supplementing thyme oil or mixture of thyme and lavender had no significant effect on live body weight (LBW) at the end of trial, while feed intake was significantly reduced, and feed conversion ratio was significantly improved compared with the control and lavender groups. Also, thyme and mixture group significantly increased thymus and bursa of Fabricius relative weights. Total blood protein, total albumin and total globulin were significantly increased by adding thyme or mixture of oils to broiler diet. Whilst, total cholesterol, triglyceride, LDL were significantly decreased, and HDL was significantly increased by adding thyme oil to broiler diet.