Poly epsilon-caprolactone (PCL) nanofibers containing metronidazole benzoate (MET) were successfully electrospun and evaluated for periodontal diseases. Solutions of 10.5% w/v PCL and 5-15% w/w MET in mixtures of dichloromethane (DCM)/N,N-dimethylformamide (DMF) with ratios of 90:10, 80:20 and 70:30 v/v were prepared, and the nanofibers were produced by electrospinning technique. Scanning electron microscopy (SEM) was used to investigate the morphology and average diameter of the electrospun nanofibers. DSC results indicated a molecular dispersion of MET in the PCL nanofibers and showed a decrease in crystallinity of PCL nanofibers by adding MET. Results showed that an increase in the DCM:DMF ratio led to a decrease in the solution conductivity and an increase in the solution viscosity as well as in the nanofibers diameter. Also increasing metronidazole benzoate concentration caused an increase in the solution conductivity and a decrease in the solution viscosity as well as in the nanofibers diameter. In vitro drug release studies in phosphate buffer solution (pH 7.4) showed that the drug release rate was affected by the solvents ratio and the drug concentration. Moreover, the burst release was low, and sustained drug release was prolonged to at least 19 days. (C) 2010 Elsevier B.V. All rights reserved.