Waste polymeric material, classified as secondary raw material, mainly consisting of selected polyolefins, PE and PP, and PET has brought great pressure on the environment, due to the large quantities produced by the urban lifestyles and economic activity. This research evaluated the possibility to reuse the plastic waste as aggregates in hydraulic lime based composite mortars.The composite mortars were prepared by replacing the conventional aggregate, silica sand, with 10, 15, and 20 % of fiber polymeric waste in a mixture of lime and water. The chemico‐physical interaction between the recycled plastic aggregates and the lime matrix was examined through FTIR, X‐Ray diffraction and morphological analyses. The effect of fiber polymeric waste on the degree of hydration and mechanical performances of the produced composites was also evaluated. Experimental results show that the good chemical interaction between the fiber plastic aggregates and the mortar induced an improvement of ductility of mortar composites. However, the plastic waste limited the degree of hydration of the hydraulic lime, due to the organic characterof the plastic as opposed to the inorganic character of lime. © 2014 American Institute of Chemical Engineers Environ Prog, 33: 1445–1451, 2014