Many orchids species were threatened because of environmental changes and the appearance of microbial diseases. Reduction in orchard yield and productivity depends on biotic factors like bacteria, viruses and nematodes, and pests. The yield losses range from 20 to 40% in global orchard production. Diseases causing crop orchid losses were epidemics with long term and massive effects. Many species of microbes were associated with orchids that are pathogenically resulting in symptoms of many diseases like brown spot, root rot, soft rot, brown rot, wilt, and anthracnose. This chapter will discuss diseases associated with Orchidaceae species that resulted from pests and other microbes and different biological managements for these diseases.