Objectives. The objective of this study was to compare the retentive force of clasps made from thermoplastic resin polyether ether ketone (PEEK)and cobalt–chromium (CoCr) alloy by using the digital force meter.Methods. On an acrylic experimental model showing maxillary kennedy class III, 34 frameworks of unilateral partial denture were made from two different materials, where 17 frameworks were fabricated from Co-Cr alloy and 17 frameworks were fabricated from thermoplastic resins (PEEK-BioHPP). Frame works were standardized with circumferential clasps in undercut of 0.02 of an inch and same thickness (1.0 mm thick) of clasp arms through using the same readymade wax patterns on all.Data management and statistical analysis were performed using Statistical Package for Social Sciences (SPSS) vs. 21. Numerical data were summarized using means and standard deviations and ranges. Comparisons between the 2 groups with respect to normally distributed numeric variables were done using the paired t-test. Results. The results of paired t test for comparison between the retention values of both Group A and Group B showed that the difference between the two groups was statistically significant and p-value ≤ 0.001. clasps of Cobalt chromium alloys showed higher retention values compared to clasps of polyether ether ketone (PEEK).