The mosquito repellent potential of plant materials, including essential oils, has been exploited for centuries. However, due to the volatility of essential oils, the protection against mosquitoes is short-lived. This study aimed to formulate citronella oil (CO) (Cymbopogon nardus) and palmarosa oil (PO) (C. martini) in the form of nanoemulgel (NEG) to delay their volatility and prolong protection time against mosquitoes. Nanoemulsions (NE) of both essential oils were prepared using ultrasonication after suitable hydrophilic-lipophilic balance (HLB) selection and phase diagram development. NEGs were formulated by mixing NEs and Carbopol 934 gel. Physicochemical characterizations, including in vitro release and permeation studies were conducted. Tween 80, Transcutol P and distilled water with 40 % glycerol were selected as surfactant, co-surfactant and aqueous components of the NEs, respectively. HLB values of 11 and 12 were found to be appropriate for CO and PO NEs preparation, respectively. The NEGs were kinetically stable and the formulation components were chemically compatible with each other. The NEG formulations prolonged the release of both essential oils for 24 h and significantly reduced the percentage permeation via cellulose acetate membrane as compared to NEs. Consequently, NEG could be a potential formulation to prolong the mosquito repellent activity of essential oils.