Digestates produced from the anaerobic digestion (AD) of manure can be reused as fertilizer. However the potential presence of pathogens in these organic waste products (OWP) and their ability to regrow during long-term storage may constitute a health hazard. This study aims to investigate the factors which may influence the survival of pathogenic bacteria during storage of by-product of AD. Eight OWP were sampled from agricultural AD plants. They were inoculated with Salmonella Derby and L. monocytogenes and incubated at 24°C. The results show a decline in the number of the two strains during storage (4.5-6 Log reduction in 7-20 days). Pathogen survival has been analyzed with regards to the degree of stabilization of organic matter and the residual microbial activity. The results showed that both biotic and abiotic factors have an effect on the survival of the pathogens and that the survival of Salmonella Derby is not influenced by the same factors as L. monocytogenes.