In order to assess interobserver and intraobserver reliability of an evaluation system of the International Clubfoot Study Group, 30 children treated for unilateral clubfoot and their radiographs were examined by three different observers. The mean intraobserver kappa value was found to be 0.62. The mean interobserver kappa value was 0.73. These kappa values correlated with a substantial degree of agreement. Interobserver reliability for all subgroup evaluations (morphologic, functional and radiological) and total scores was 90% or over. This also indicates a good interobserver reliability. In conclusion, the Bensahel et al. and International Clubfoot Study Group outcome evaluation system may be used reliably for the assessment of outcome of the treatment of clubfoot.