Objectives: The case-control study was to assess the periodontal parameters, plaque score, bleeding on probing, probing pocket depth, gingival recession and loss of attachment of teeth in contact with acylic partial dentures and to compare with teeth in the contra lateral side of the same arch not in contact with denture base. Methods: The sample consisted of partially edentulous 10 males and 12 females between the ages of 21 and 43 years. The prosthetic treatment was carried out with maxillary acrylic partial dentures which were designed in such a way that the gingival margin of two teeth on one side of the arch was in contact with the acrylic denture base (control side). The same teeth on the contra lateral side of the arch were kept well relieved from the denture base (6x10mm in bucco-medial and antero-posterior dimensions respectively on the test side). Initial periodontal assessment with plaque score (PLS), bleeding on probing (BOP), probing pocket depth (PPD), gingival recession (GR) and loss of attachment (LOA) was carried out prior to issue of the partial dentures. All patients were recalled at 2 weeks, 3 months and 6 months intervals after issuing the dentures. Similar readings on periodontal parameters were obtained at each visit. Paired t test, Bonferroni t test and chi square were used for statistical analysis. Results: PLS, BOP, PPD, GR and LOA were increased significantly on the control side with 3 and 6 months of denture wearing (p<0.05). No difference in parameters was observed at 2 weeks recall. The changes of all parameters in the test side were non significant. Conclusion: With increased duration of denture wearing, removable acrylic partial dentures tend to adversely affect periodontal parameters, and therefore it is recommended to keep the dentures well relieved, at least 6x10 mm, from the gingival margin, wherever possible.