Background: The study was conducted to compare the accuracy of one step putty wash impression technique with two step impression technique with three different addition silicone impression materials (Affinis , Flexceed and photosil). The measurements of the precision stainless steel die and gypsum product dies, prepared from two different techniques with three different impression materials were evaluated by standard microscope measurements at three different location. Materials & methods: A stainless steel precision die (Figure 8) with a brass base was fabricated which mimicked a three unit preparation. A perforated metal tray (Figure 9) was fabricated for making the impression of the precision die. A total of 90 specimens were prepared which were divided into six groups of fifteen specimens each: Group A1: One step impression technique with Affinis,Group A2: Two step impression technique with Affinis.,Group B1: One step impression technique with Flexceed., Group B2: Two step impression technique with Flexceed, Group C1: One step impression technique with Photosil, Group C2: Two step impression technique with Photosil. The readings obtained were tabulated and subjected to statistical analysis using one – way ANOVA and Tukey’s post hoc tests. Results: One way ANOVA demonstrated highly significant values among the study groups (p<0.001) both when comparing inter abutment distances (AB, BC, AC) as well as for differences as compared to the stainless steel precision die .Post hoc test for multiple comparisons between the mean differences of all groups. Highly statistically significant differences were seen between the means differences for all the study groups. Conclusion: The present study was a step towards comparing the three different addition silicone impression materials with one step and two step impression technique for their dimensional accuracy.