The disintegration of Biopol-coated cardboard, polylactide fabric and film was studied using three different procedures: adding the samples directly to the compost pile, and placing them in the pile in nylon bags as well as in steel frames. Cellulose-based sausage casing, polyethylene and Mater-Bi ZF03U were also tested in steel frames as reference samples. Direct addition of the samples to the compost pile had no detrimental effect on the decomposition of compost biowaste. The use of steel frames proved to be good a method for testing samples like packaging materials. Both polylactide samples and Biopol-coated cardboard degraded completely in the steel frames. The results showed that composting activity parameters should be followed during composting before any conclusions can be made about the compostability of the samples. The compost produced from the polymer samples showed no toxicity in the plant growth test with barley and radish seeds performed at the end of the experiment.