Methods of treating sleep disorders, particularly certain aspects of insomnia, in elderly patients (65 years and older) by administering initial daily dosages of doxepin of 1-3 mg. These ultra-low initial dosages are more effective in elderly versus non-elderly patients in decreasing wake time during sleep, latency to persistent sleep and wake time after sleep, and are particularly efficacious in treating those conditions in the last hour of an 8-hour sleep cycle. Also, the dosages described herein are safe for elderly individuals.