Abstract: Sodium azide induced polygenic variably was studied on promising wheat variety HD-2733 in two subsequent cropping seasons during 2007-2009. For chemical treatment, 100 genetically pure seeds were soaked in distilled water for 6 h, blotted dry and treated with freshly prepared mutagenic solution of 0.02, 0.04% and 0.06% concentration In laboratory germination, root length and shoot length was observed. Among the different concentration of sodium azide, the highest germination was recorded at control (99.55%) followed by 0.02% concentration (97.11%), 0.04% concentration (95.55%) and lowest at 0.06% concentration (85.77%). Higher concentration of sodium azide reduces the germination percentage, root length and shoot length; however, at low concentration it was at par with control. The magnitude of genotypic and phenotypic variability, heritability and genetic gain for various polygenic traits were also decreases with the increases in concentration of sodium azide. However, yield attributing characters showed both positive and negative shift in mean than those of control. Some of the mutant lines (eight progeny for earliness, one for plant height, three for spike length and grain yield each, two for tillering and four for test weight) were found desirable. These lines were either comparable to or better than control for yield and its components. It is concluded that sodium azide with 0.02% concentration appear to be the most effective mutagenic treatment for induction of micro-mutation in yield component traits and selection in M2 populations of these treatment would be effective in rectification of simply inherited morphological deficiencies and bringing out lines with yield improvement.