Microbial endophytes have been extracted from three classes of plants: (1) plants growing at high altitudes(>8100 ft); (2) poisonous plants, and (3) medicinal plants. Many of these endophytes synthesize compounds that show bio-active activity against fungi, bacteria and a HeLa cancer cell line. Descriptions will be given of the isolation and purification, bioactive testing and identification of the endophytes and the compounds they produce.