Nanofibrous scaffolds have many advantages that make them excellent candidates for tissue engineering applications. The scaffolds with high surface area to volume ratio favor cell adhesion, proliferation, migration and differentiation. In the present study, the preparation of electrospun poly (epsilon-caprolactone)-polyethylene glycol-poly (epsilon-caprolactone) (PCL-PEG-PCL) nanofibers is shown for the first time. PCL-PEG-PCL copolymers were synthesized using a ring-opening polymerization method. The polymers were characterized by FT-IR, H-1 NMR and DSC. Nanofibers with mean diameters ranging from 60 to 170 nm were obtained by the electrospinning method. Their morphology was evaluated by scanning electron microscopy (SEM). An MTT assay was used to compare the number of cells in the nanofiber scaffold. It was found that the morphology and diameter of the nanofiber depended on the chemical composition and molecular weight of the PEG segment of the copolymer used for electrospinning. Increasing the molecular weight of PEG blocks from 2000 to 6000 led to a decrease of the diameter of the fibers and the formation of beads.