<p>The accumulation of microplastics (MPs) in terrestrial systems can change the availability of metal(loid)s. The goal of this study was evaluated the effect of 1% (w/w) polyethylene MPs (PE–MPs) on Cu²⁺ adsorption–desorption processes in two agricultural soils (Andisol: ANDI and Mollisol: MOLL). Batch Cu²⁺ adsorption–desorption experiments were conducted using AnDI And MOLL soils with and without 1% (w/w) PE–MPs addition. The results revealed, for&#xa0;the&#xa0;very first&#xa0;time, that the adsorption of Cu²⁺ in both soils with 1% PE–MPs is slightly higher than in the soils without MPs. The adsorption kinetic studies of Cu²⁺ in soils in the absence And presence of 1% PE–MPs fitted well to the pseudo–second–order model (r² ≥ 0.940 and ꭓ² ≤ 14). The Langmuir model described the adsorption isotherms of Cu²⁺ in both soils in the absence And presence of 1% PE–MPs (r² ≥ 0.982 and ꭓ² ≤ 7). According to this model, the maximum adsorption capacity showed the following trend: ANDI + 1% PE–MPs &gt; ANDI &gt; MOLL + 1% PE–MPs &gt; MOLL, reaching values of the order of (mmol kg⁻¹): 51.77 &gt; 48.85 &gt; 39.10 &gt; 37.75, respectively. The Cu²⁺ desorption percentage showed the following trend MOLL &gt; ANDI + 1% PE–MPs &gt; MOLL + 1% PE–MPs &gt; ANDI, suggesting that Cu²⁺ desorption from soils by adding 1% PE–MPs was soil type–dependent. This study demonstrated, that PE–MPs could favor the accumulation of Cu²⁺ in MOLL soils and increase the mobility/availability of Cu²⁺ in ANDI soils.</p>