Polymeric nanofibers as a matrix for controlled release of pesticides has gained importance alongside controlled drug release. Electrospinning of thiram pesticide incorporated polycaprolactone micro and nanofibers and thereof release characteristics are reported. With only chloroform as the solvent for polycaprolactone, thiram incorporated microfibers could be electrospun. To electrospin polycaprolactone nanofibers containing thiram, methanol was added as a co-solvent. Regular and beadless microfibers (mean diameter = 3.7-4.5 μm) and nanofibers (mean diameter = 29-481 nm) were successfully electrospun. Fourier-transform infrared spectroscopy showed that thiram was held by the polycaprolactone matrix physically. X-ray diffraction analysis showed that thiram could not reorganize its crystals in the fibrous matrix. The amount of thiram pesticide loaded in micro and nanofibers was measured to be in the range of 42.5-150 and 26.4-163.4 mg.g À1 , respectively. Microfibers showed a higher release rate with lower amounts of the loaded thiram. Nanofibrous matrices showed an opposite trend.