Malaria is a parasitic disease that is mostly endemic in Africa where approximately 90% of global malaria deaths occur. One of the reasons malaria is still endemic in Africa is because of outdoor mosquito bites. These mosquitoes typically bite on the ankle and foot area because they are attracted to foot odour. Topical repellents may be used to reduce outdoor mosquito bites. However, they have a short residual efficacy that lasts a few hours and they require repeated application to maintain effective residual efficacy. This makes topical repellents expensive for use by low-income people where malaria is most prevalent. It is possible to extend the residual efficacy of topical repellents through controlled release. This study focused on the development of long lasting and affordable repellent impregnated bicomponent polymer fibres. These fibres were knitted into socks that can be used to prevent ankle and foot bites by mosquitoes. The approach was to spin a bicomponent polymer fibre consisting of a core polymer (poly(ethylene-co-vinyl acetate)) impregnated with approximately 40 wt.% N,N-Diethyl-meta-toluamide, and a sheath layer (high density polyethylene) that acted as a semi-permeable barrier which reduces the rate of repellent release to the atmosphere. Scanning electron microscopy studies indicated that a bicomponent core-sheath structure was successfully formed. Raman studies showed the presence of a concentration gradient on the fibre cross-section. This was evidence of controlled release of the repellent. Laboratory scale mosquito repellency tests revealed that textile manufactured from these fibres can retain repellent efficacy after 20 cold water washes or 7 months ageing under room conditions. Controlled release via bicomponent fibres was found to be an effective and affordable technique for extending the residual efficacy of topical repellents. This technique may provide a practical outdoor mosquito control tool for use by poor communities in Africa.