The incorporation of non-recyclable plastic wastes in bituminous mixtures was investigated. It aims to develop a mixture with greater performance than the reference ones, supporting its incorporation in bituminous mixtures. Ten different samples of plastic waste were selected in a waste treatment centre, with only one having commercial value, while the others were either landfilled or incinerated. Six of the samples presented a heterogeneous composition, while the others were homogeneous. Samples were visually separated by type of residue, colour and using the density test with water, resulting in 75 samples. An initial evaluation of the plastics’ melting point was performed to assess their suitability for incorporation using the wet method. Samples that could be incorporated without requiring excessive heating of the bitumen were chosen, particularly sample B, which started melting at 120 ºC. Three other homogeneous samples were selected with thermoset, polyurethane and high-density polyethene. Subsequently, samples were prepared by combining nominal penetration bitumen 50/70 with different percentages of sample B and penetration and softening temperature tests were conducted. The obtained results demonstrated that the wet method did not incorporate effectively the plastics due to their inability to melt into bitumen fully. The study will proceed to incorporate the plastic waste using the dry method.