Current environmental aspects of parasitological and mycological diseases, diagnostics problems and some mechanisms of pathogens' action facilitating invasion of human organisms have been presented. Imported humans parasitoses, difficulties in diagnosis and treatment, possibility of expansion of the endemic pathogens' occurrence ranges have been discussed. Mycological topics included evaluation of the role of birds as vectors of potentially pathogenic fungi in biosphere, threats connected with biofilms formation in hospital and home environments, and interrelations among microorganisms in such biofilms.