Conventional insect repellent treatments for fibers, fabrics, and garments suffer from limited durability to repeated laundering and, depending on the insecticide, potential irritation, or toxicity. In this work, electrospinning was employed to control the composition of hierarchically structured functional microscale to nanoscale fibers for tunable insect repellent release by physically incorporating picaridin into nylon-6,6 nanofibers. The size and morphology of nylon fibers were unaffected by picaridin incorporation, even at loading concentrations up to 50 wt%. Picaridin release kinetics were largely dependent on loading concentration and temperature, as picaridin-nylon intermolecular interactions were minimal affording diffusion based release. Coaxial nanofibers, in which the sheath component has potential to protect additives in the core for more durable fabrics and act as a diffusion barrier for extended release applications, were also developed and demonstrated altered release kinetics compared to monofilament analogues, indicating the capability to further tune release behavior.