A maxillary photoelastic model was constructed to determine the retention and force transmission characteristics of a bilateral distal extension base partial denture. Comparisons were made using palatal and labial I-bars. It was shown that there were no significant differences in retention and force transmission between palatal and labial I-bars. From a stress and retention standpoint, it may be concluded that the use of palatal I-bars is a viable alternative to the labial I-bars, especially where aesthetics is of primary concern.