Methods and kits are provided for diagnosis of specific cancerous conditions. The invention features a method for diagnosis of a condition in a patient associated with an elevated level of telomerase activity within a cell. The method involves determining the presence or amount of telomerase within the cells in the patient, e.g. by the use of the polymerase chain reaction. In one embodiment of the invention, the condition associated with elevated telomerase activity is chosen from prostate cancer, breast cancer, colon cancer, renal cancer, ovarian/cervical cancer, lung cancer, and leukemia. The invention allows cancer to be detected even in tissues and cells which are not positive by pathology.