Each of plant products was applied onto the forearm and they were evaluated. The results for plant oils repellency against A.aegypti were summarized in Table 1. Ylang ylang oil containingcoconut oil provided longer lasting complete repellency (88.7 min)while the ylang ylang oil containing olive oil and lemongrassoil containing coconut oil which gave complete protection for 85.5 min. In addition, both products of lemongrass oil containingsoybean oil and olive oil gave complete repellency for 72 min and60 min, respectively. However, there were not significant differ-ences in the protection time among the repellents against A. aegypti(P > 0.05). WHO standard (2009) determines the repellency timeagainst A. aegypti mosquitoes should be more than 2 h; none of therepellents met this requirement. DEET, which is the best-knownsynthetic insect repellent, at 20% concentration of active ingredi-ent, provided the longest-lasting complete protection for 155 minor more than 2 h after application. Unfortunately, IR3535, which isthe commercial insect repellent, at 12.5% concentration of activeingredient, showed no repellency against A. aegypti (3 min).