Aromatase inhibition is an established endocrine treatment modality in postmenopausal breast cancer and is currently considered as an interesting experimental treatment approach in other malignant conditions such as endometrial carcinomas and prostatic cancer. While the 'classic' aromatase inhibitor aminoglutethimide causes many adverse effects that makes it unfit for use in elderly patients, several novel aromatase inhibitors with minimal adverse effects are currently being investigated. These drugs may provide important new tools in the endocrine treatment of malignant diseases in aging patients.