The research work was carried out to investigate the behaviour of bituminous concrete mix with addition of waste plastic bottles made up of Polyethylene Terephthalate (PET) via dry process. Marshall moulds were prepared with bitumen content 5.0 to 5.8% (with 0.2% increment) and waste plastic content 0%, 4%, 6%, 8%, 10%, 12% and 14 % by weight of bitumen. Mechanical properties required for an ideal mix were determined. Results show that with increase in quantity of PET, mechanical properties of bituminous concrete mixes improve initially up to certain extent. The optimum bitumen content for conventional mixes was found to be 5.66%. Modified mix of 8% PET content with 5.40% bitumen content fulfils the requirements of modified mixes as per IRC SP-98, 2013 specifications. Bitumen content reduced to be 4.59% with addition of waste plastic bottle in bituminous concrete mixes. Hence, application of plastic waste in bituminous pavements is environmental friendly solution in terms of disposal of non-biodegradable waste plastic along with improvement in mechanical properties of bituminous mixes.