Selected elements of simplified, bacteriological diagnosis of diphtheria were presented. The procedure of Corynebacterium strains isolation from diphtheria suspected persons and performing of toxin testing of potentially toxigenic isolates: C. diphtheriae, C. ulcerans and C. pseudotuberculosis were shortened. The role of selective tellurite media was underlined but Loeffler medium was rejected. Columbia blood agar plate was utilized for preliminary culture. Biochemical tests and toxin testing were performed from this medium. Presented diphtheria diagnosis scheme may have practical application for the laboratory work in Poland.