Straw is one of the basic materials used in the process of composting. Both it has a structure formative role and enables the proper aeration of the heap interior, and is a provider of organic carbon indispensable in intense processes of microbiological changes. It is especially important because the sewage sludge is a waste with very high content of nitrogen and deficiency of carbon. Meanwhile, one of the biggest problems in working sewage sludge composting plants is a high market price of cereal wheat which makes difficult the application of doses recommended by the experts. Hence the aim of this paper is to study the composting applicability of different straw kind in the aspect of composting process run dynamics and size of ammonia gaseous emissions. The paper presents the research results of composting process as well as ammonia emission from sewage sludge composted in mixtures with cereal straw, fresh maize straw, dried and rape straw along with a supplementary additive of sawdust. It has been stated that different kind of straw are suitable to use in composting process of sewage sludge and because of potentially lower purchase price can be a very good alternative for traditionally used cereal straw.