Abstract: The use of synthetic detergents is on increasing ladder due to shift from soaps to detergents. Linear Alkylbenzene Sulphonates (LAS) are one of the major anionic surfactant and used as active ingredients in household and personal care products. LAS may reach the soil environment due to its widespread use and disposal. In soil microcosm study LAS at different concentrations were added to the test soil and total bacterial, fungal and actinomycetes counts were recorded at different intervals. Bacteria showed high sensitivity to LAS exposure concentration, compared to fungi and actinomycetes. Soil dehydrogenase activity was also recorded and found that LAS treatment reduced dehydrogenase activity significantly. The correlation between heterotrophic bacterial count and dehydrogenase activity was done using a matrix of Pearson’s correlations coefficient. Though at lower concentrations a positive correlation was noted between the enzyme activity and bacterial count, at higher LAS concentrations a negative correlation was observed. Further studies are needed in order to evaluate the effects of LAS on soil quality.