Abstract: Folk medicine claims that some foods can improve the health status of patients with asthma, examples being marjoram and lettuce seeds oils. The present study aimed to investigate the effect of these oils on asthma outcome. A sample of thirty patients with asthma (15 females and 15 males) aged 42.6±1.84 years was chosen from outpatient clinics of Tanta University Hospital, Egypt. All patients were diagnosed according to lung functions, blood variables, and clinical signs as being asthmatic. The patients were randomly divided into three equal groups; control group (CG); marjoram group (MG), who received two drops of marjoram oil daily; lettuce group (LG), who received 5 ml of lettuce seeds oil daily. The supplementation continued for three consecutive months. Lung functions (forced vital capacity (FVC), maximum voluntary ventilation (MVV), and peak expiratory flow rate (PEFR) were measured at baseline and after the supplementation. Blood eosinophilic cell counts and IgE concentration were also determined at baseline and after 3 months of supplementation. The results revealed that the majority of subjects were of intermediate socio-economic status (53.3%), and had suffered from asthma for 14.6±6.3 years. FVC increased significantly (P<001) after the supplementation for all groups particularly for MG. On the other hand, MVV increased significantly (P<0.001) for MG (by 7.34%) and LG (by 2.63%), while it decreased by 4.3% for CG. Moreover, PEFR increased significantly for all groups, the highest increment being for CG (9.4%). Eosinophilic cell counts decreased significantly for all subjects, particularly for MG (-42.7%) as compared with CG and LG (-19.7% and -21.9% respectively). Finally, the IgE concentration decreased significantly (P<001) to normal levels for MG and LG. In conclusion, data suggests that administration of marjoram oil at a safe dose (two drops daily) was effective in improving the health and lung functions of adult patients with asthma.