The objective of this study was to determine the biodegradability of bioplastic materials – sponge cloths – available on the European market that are labeled as 100% biodegradable but not certified as compostable. The test was carried out in a controlled composting environment. The project length was 22 weeks. The emphasis was put on discovering whether the sponge cloths are biodegradable or not. Based on the results thereof it can be concluded that sponge cloths have not decomposed completely but their color has changed and that degradation and physical changes occurred. Samples A₁, and A₂ have not decomposed completely and exhibited very slow degradation rate. Sample B₅ exhibited the highest degradation rate. Samples B₃, B₄ exhibited high degree of decomposition. The main conclusion from this study is that biodegradation of bioplastics materials strongly depends on both the environment in which they are placed and the chemical nature of the material.