The Aim of the study: The aim of the study was to compare the effect of two different border molding materials on the retention of maxillary complete dentures. Material and Methods: The study was carried out on ten completely edentulous patients. Each patient received one mandibular and two maxillary dentures (D1, D2). D1 maxillary denture was made from a secondary impression using putty rubber base as a border molding material, while D2 maxillary denture secondary impression made using green stick compound as a border molding material. The retention was measured by a digital compact force gauge, which applied a pulling force on a metallic hook attached to the geometric center of the maxillary dentures. The geometric center was determined using AutoCAD computer program. Measurements were taken at time of denture insertion. The data were collected, tabulated and statistically analyzed.Results: The mean retention value for D1 dentures was 1971±460.2 at time of denture insertion while for D2 dentures the value was 1555±599.6. Statistical analysis revealed a significant difference between the retention of both dentures with clear superiority of the putty rubber base impression material. Conclusion: Within the limitations of this study, it has been concluded that border tracing with putty rubber base produced more retentive maxillary complete dentures as compared to green stick compound. Keywords: Retention, maxillary complete denture, border molding materials.