An examination of the records of the Laboratory Diagnostic Service for the past ten years reveals that a number of diseases which were scarcely known to exist or were unknown at the beginning of the period are now of major importance to the turkey industry. A list of such diseases includes coccidiosis, hexamitiasis, infectious sinusitis, moniliasis, paratyphoid infection, pullorum disease, swine erysipelas, trichomoniasis, ulcerative enteritis, and so-called unknown disease. Enterohepatitis (blackhead) still undoubtedly is the most important disease of turkeys, but the time when it was the only disease of turkeys which merited serious consideration has passed. During the past five years more cases of coccidiosis than of enterohepatitis have been directed to the attention of the laboratory. This does not mean that coccidiosis is more prevalent than enterohepatitis because the latter is usually more readily recognized by growers of turkeys and specimens may not be submitted for laboratory examination.