Five locally isolated strains SBI (1-5) were cultivated on mineral salts-agar with polyurethane as the sole carbon and energy source. All the tested microorganisms grew on polyurethane except SBI-4. However, the growth inhibition of SBI-4 was temporary. Except of SBI-4, all microogrganisms grew and prossessed esterase activity when cultured on mineral salts medium containing polyurethane or on an enriched medium. When SBI-5 isolate was allowed to grew in mineral salts liquid culture media containing poiyurethane-painted aluminum coupons, a change in color as well as an increase of total protein and optical density of the culture broth were evidences for biostripping of the polyurethane coating. Immobilization of SBI-5 cells on polyurethane-coated coupons with the aid of a thin layer of calcium alginate showed more stripping of the dark colored coating of the aluminum coupons than that obtained with free suspended cells. Scanning electron microscopy of microbially treated polyurethane painted coupons revealed a reduction of the originally hillet's surfaces.