Effects of quarry dust and polypropylene fiber on compaction properties, shear strength parameters, and California bearing ratio (CBR) of a fly ash have been discussed in this paper. Quarry dust was added to a fly ash from 0 to 60% at an increment of 10%, compaction and soaked CBR tests were conducted on fly ash-quarry dust mixes and the optimum percentage of quarry dust was found out to be 40%. Polypropylene fiber was added to fly ash stabilized with optimum percentage of quarry dust, from 0 to 1.5% at an increment of 0.25%. Compaction, shear strength and soaked CBR tests were conducted on fly ash-quarry dust-polypropylene fiber mixes. From the test results the optimum percentage of polypropylene fiber was found out to be 1%. At the optimum percentage addition of quarry dust and polypropylene fiber there is slight decrease in maximum dry density and optimum moisture content, 28% increase in cohesion, 45% increase in angle of internal friction, and 597% increase in soaked CBR of the fly ash.