Abstract Introduction: Acid etching plays an important role in improving the retention of composite resin to the tooth by increasing the surface roughness and better penetration of the dentin bonding agent into the tooth substrate. Solution form of acid etchant has better surface wetting property than gel form whereas gel form has the advantage of ease of application. Aim: To evaluate the shear bond strength of composite resin to dentin subjected to two different viscosities of Phosphoric acid etchant. Methodology: Forty non-carious, intact human maxillary premolars that were recently extracted were selected for the study. The prepared specimens were mounted on self-curing polymethyl methacrylate resin to embed the root portion. The occlusal surfaces of the teeth were ground using a water-cooled trimming wheel to create flat surfaces at a depth of 1.5 mm from the cuspal tip. The teeth were then randomly divided into four groups of ten specimens each, based on the type of etchant used. Group I received Etching Gel (Prevest Denpro Actino), Group II used Etching Liquid (Prevest Denpro Actino), Group III used Etching Gel (Prime Dental), and Group IV used Etching Liquid (Prime Dental). For bonding, Prevest Denpro Fusion Bond 5 was applied to the specimens in Groups I and II, where as Prime Dental Restorite Bond 5 G was applied to the specimens in Groups III and IV, following the manufacturers' instructions. Filtek Z350 composite (3M) was placed in increments on all 40 specimens and cured for 20 seconds. The specimens were stored in a distilled water bath at a controlled temperature of 37°C for 24 hours. Finally, each specimen underwent shear bond strength analysis using a Instron Testing Machine at a crosshead speed of 1.0 mm/minute. Statistical Analysis: The difference in shear bond strength was calculated using One-way ANOVA and Paired Sample T test. P-value >0.05 Results: On intragroup and intergroup comparison, Group 4 had the highest mean maximum force (33.1380 N), followed by Group 2 (29.4510 N), Group 3 (20.8050 N), and Group 1 (16.9990 N). There was a statistically significant difference in maximum force among the groups. Group 4 also exhibits the highest mean compressive stress (10.6540 MPa), while Group 1 has the lowest (5.6820 MPa). The p-values indicate that these differences are statistically significant (p < 0.001). Conclusion: Within the limitation of this study, it can be concluded that Prime liquid solution provides maximum shear bond strength of composite to dentin.