BACKGROUND Prevention of arthropod-borne infections hinges on bite prevention. We aimed to investigate travellers' use of repellents. METHODS We measured the amount of applied repellent with a spray containing 30% DEET and 20% Icaridin versus a lotion with 20% Icaridin alone. We calculated the concentration of active ingredient reached on the skin and evaluated formulation acceptability. The travellers completed a questionnaire evaluating Knowledge, Attitudes and Practice (KAP) to anti-vectorial protective measures (AVPM). RESULTS Some 200 volunteers travelling to mosquito borne infection endemic areas were recruited. The mean concentration of active substance achieved on the skin of the left arm was 0.52 mg/cm of DEET/Icaridin spray versus 0.21 mg/cm of Icaridin lotion. These levels are below the recommended protective dose (1 mg/cm) for each formulation. Women were significantly more likely to apply a higher, protective dose of repellent. Travellers to Africa, women and older participants showed higher projected adherence to AVPM. CONCLUSIONS Only 2.5% of recruited travellers applied the recommended protective dose of repellent. Women and older travellers are the most adherent users of repellents. The pre-travel health consultation should provide more information on the application quantity and correct use of repellents.