People are in constant contact with soil either directly or indirectly through food, water or air. Soil can act as a carrier or reservoir of important human diseases, particularly intestinal ones. The risk to public health arising from application of insufficiently treated animal manure to soil may be higher than detected by common methods. With regard to animal wastes we are concerned particularly with representatives of the family Enterobacteriacea, the majority of which have zoonotic character and endoparasites that may cause massive parasitic infections in both specific hosts and nonspecific ones, such as humans. Therefore model bacterial strains survival (Salmonella typhimurium) and helminths eggs viability (Ascaris suum) in the course of long-term storage of pig slurrywas investigated. The experiments were carried out on the raw pig slurry obtained from pig farm. The slurry with model micro-organisms was stored for 115 days in closed plastic containers of volume 5 litre at the following temperatures: - in a refrigerator at 4oC, - in a thermostat at 20oC, - in a thermostat at 42oC. The initial concentration of the tested S. typhimurium strain (3.6 x 105 CFUml-1) in pig slurry stored at 4° C decreased by day 90 by three orders of magnitude and on day 115 of storage the test strain was no more recovered. The tested strain survived in slurry for less than 115 days at 20°C. The most marked decrease in plate counts of bacteria was recorded in pig slurry stored at 42°C. Our results showed decreased survival of S. typhimurium in pig slurry during storage at 20o and 42°C. This indicated that viability of bacteria in stored pig slurry was affected first of all by the temperature during the storage. Increased temperature is an important factor contributing to devitalization of indicator micro-organisms. Our study showed that the number of devitalised Ascaris eggs generally increased with the length of storage and the temperature. However, considerable number of Ascaris eggs remained viable even after 115 days of storage at 4o and 20oC. Only at 42oC more than 90 % of eggs were devitalised after 12 days of storage. However, such temperature can only rarely be reached in animal slurries, thus the risk of persistence of this parasite is really high. This hazard increases when raw slurry is used for fertilization of soil or pastures. Aknowledgement: This study has been realized thanks to the financial support of the project VEGA No. 2/0140/13.