Pyrogenic silica and organoclay nanocomposite strands containing liquid mosquito repellents were prepared by a twin-screw extrusion compounding. The mosquito repellents included DEET, Icaridin, IR3535 and ethyl anthranilate. They were immobilised in the pores of a microporous polyolefin matrix. The nature and levels of the repellent and nanofiller employed affected the material phase morphology. The repellent release was followed as a function of ageing time in convection ovens set at 50 oC. The release rates were well described by a mathematical model that considered the microporous internal structure. In most cases, the integral skin covering the strands determined the repellent release rate. The strands provided effective mosquito repellence for more than ninety days. The implication of these findings is that ethyl butylacetylaminopropionate (IR3535) or Icaridin are attractive candidates for long-lasting wearable mosquito repellent devices. Key words: Mosquito repellent; DEET; Icaridin; IR3535; ethyl anthranilate; nanocomposite; slow release