Controlled release of pesticides is eco-friendly and cost-effective. Thiram is a pesticide for fighting fungi and protection of cultivated products. This research aimed at controlled release of thiram pesticide from Poly (L-lactic acid) (PLLA) nanofibrous matrix. Solutions of PLLA (9% w/v) in chloroform-methanol (80-20 v/v) containing 5, 10, 15, 20, and 25% (w/w) thiram relative to the PLLA were electrospun. FESEM, FTIR, and XRD were employed to characterize the electrospun nanofibers. UV spectrophotometry was employed to study the release of thiram from PLLA nanofibers in deionized water. The results showed that the controlled release of thiram from PLLA nanofibers without annealing followed Fick mechanism, but after annealing, non-Fick mechanism prevailed. It was also observed that annealing led to lower level and lower initial rate of controlled release. It is concluded that electrospun PLLA-thiram nanofibers can be used for the controlled release of thiram in long-term periods in agriculture.